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Full text of "Hygiene and sanitation, a text-book for nurses"

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HYGIENE 



AND 



SANITATION 



A TEXT-BOOK FOR NURSES 



BY 



GEORGE M. PRICE, M.D. 

AUTHOR OF "a HAND-BOOK ON SANITATION;" "TENEMENT HOUSE INSPECTION; 

"epitome of hygiene and public health;" "the MODERN factory;" 

DIRECTOR, JOINT BOARD OF SANITARY CONTROL; DIRECTOR OF 
INVESTIGATION, NEW YORK STATE FACTORY COMMISSION 



THIRD EDITION. REVISED AND ENLARGED 




LEA & FEBIGER 

PHILADELPHIA AND NEW YORK 

1917 

V' U 



Copyright 
LEA & FEBIGER 

1917 



7 



TO 

LILLIAN D. WALD 

THE PIONEER OF PUBLIC HEALTH NURSING IN 

THE UNITED STATES AND THE FOREMOST ADVOCATE 

FOR THE EXTENSION OF THE SCOPE OF 

THE nurse's work 

THIS BOOK 

IS DEDICATED IN APPRECIATION AND RESPECT. 



5()9( 



PEEFACE. 



The last decade has seen a wonderful expansion of 
the function of the trained nurse and a great broaden- 
ing of the scope of her usefulness. No longer are her 
duties limited to the simple care of the sick. The 
nurse has become a priestess of prophylaxis. Her work 
in preventive medicine has become invaluable. She 
has become an important factor in social, in municipal, 
and in public health work. 

No one at present denies the great utility of the 
nurse's work in the school, in the factory, in the social 
part of dispensary work, in the milk stations, in the 
preventive work undertaken by life insurance com- 
panies, and in many other public health activities 
which have been opened to her. In all these activities 
a fundamental knowledge of the principles of hygiene 
and public health is necessary for intelligent work and 
usefulness. 

This book is an attempt to give the nurse a knowl- 
edge of the elements of hygiene in its various branches. 
l)is})uted points and too detailed instructions on 
minor points have been avoided. Rules for the care 
and treatment of diseased persons have been omitted, 
as these are taught to the nurses in their regular cur- 
riculum in the training school. 



vi PREFACE 

It is gratifying to note tluit the hope expressed in 
the preface of the first edition, that the book might be 
useful to the nurse in the discharge of her manifold 
duties, has been fulfilled, as is evidenced by the need for 
a third edition within the first four years of pubhcation. 

The text of the book has been considerably changed. 
A new chai)ter on Infecrtious Diseases has been added, 
the (chapter on Personal Hygiene has been considerably 
ami)lified, the chapter on School Hygiene has been 
elaborated, and the text of the other parts of the book 
has been carefully revised and brought up to date. 

G. M. P. 

New York, 1917. 



CONTENTS 



CHAPTER I. 

Introduction to the Study of Hygiene. 

Definitions — Foundations of Modern Hygiene— Conserva- 
tion of Human Resources — Further Possible Prevention 
of Disease — The Role of the Nurse in Prophylaxis . . 17 

CHAPTER II. 

The Hygiene of Habitations. 

Influence of Housing on Health — Safety and Fire Protec- 
tion — Light and Illumination — Air — Ventilation — Heat- 
ing — Water Supply — House Drainage — Plumbing — 
Plumbing Pipes and Fixtures — Water Closets — House 
Waste Matters — House Cleaning 24 

CHAPTER III. 

The Hygiene of Foods and Food Supply. 

Dietetics and Preparation of Foods — Care, Storage and 
Preservation of Foods — Adulteration — Meat and Meat 
Supply— Milk and Dairy Products— Cow's Milk— Milk 
Products — Milk Adulteration — Milk Preservation — Milk 
Inspection and Testing 89 

CHAPTER IV. 

The Hygiene of Schools and op School Children. 

The School Child— The School Building— The Care of the 
Child in School — Functions and Duties of School Nurses 148 



vili COXTEXTS 

CHAPTER V. 

The Hygiene of Occupations. 

Occupation and Health — Industrial Factors Influencing 
Health — Specific Occujiational Dangers — Industrial Bet- 
terment — Functions and Duties of the Factory Nurse . 166 

CHAPTER VI. 

Infectioub Diseases and Their Prevention. 

I. General Considerations: The Infectious Diseases — 
Classification — Stages — Morbific Agents — Portals of 
Entry — Modes, Vehicles and Agents of Transmission. 

II. Principles and Practice of Prevention: Mortality — 
Progress in Prevention — Methods of Prophylaxis — 
Individual Immunity, etc. — Disinfection — Social 
Measures of Prophylaxis. 

III. The Role and Functions of the Nurse in Prevention of 
Infectious Diseases: Public Health Nursing — Dis- 
trict Nurses — Nursing in Tuberculosis — Measles — 
Scarlet Fever — Diphtheria — Pneumonia — Typhoid 
— Pohomyelitis — Erysipelas 190 

CHAPTER VII. 

Personal Hygiene. 

Activity and Rest — Food and Dietetics — The Caloric Value 
of Food — Elimination — Personal Hygiene of the Child — 
Personal Hygiene of the Aged — Personal Hygiene of the 
Sick 241 



HYGIENE. 



CHAPTER I. 

INTRODUCTION TO THE STUDY OF 
HYGIENE. 

Hygiene is the oldest and the youngest of all 
sciences. 

Hygiene is the oldest of all sciences because the 
preservation of life and health is an instinct born 
in the animal, and the common endeavor of human 
beings to preserve their health and to prolong their 
lives is as old as human society and dates from the 
beginning of mankind. 

Hygiene is the youngest of all sciences because it 
could only become a science when physiology, bac- 
teriology, and vital statics had been firmly estab- 
lished u])()n a scientific basis. 

Definitions. — Hygiene is the science and the art, the 
theory and the practice of the preservation and the 
promotion of human health and life. 

The aim and function of hygiene are the ])reventi()n 
of disease, the prevention of premature death, and the 
promotion of normal health in human beings. 

Hygiene may be ])ersonal or public, municipal, 
State, and Federal. We also distinguish particular 
2 



18 INTRODUCTION TO THE STUDY OF HYGIENE 

branches of hygiene, such as the hygiene of housing, 
of food, of school, of industry, etc. 

Personal hygiene is the science and the art of the 
preservation and the promotion of Individual health 
and life by the prevention of constitutional diseases 
and by the increase of the vital force and resistance 
of the human body. 

Pvhiic hygiene is the science and the art of the 
j^reservation and the ])r(miotion of public health by 
the prevention of environmental causes of disease, 
and by the improvement of conditions common to 
many ])ersons and communities. 

Sanitary science is the theoretical part of hygiene. It 
is based upon the investigations of the influence of envi- 
ronmental conditions, upon the health and life of human 
beings, and has for its aim the study of these condi- 
tions and of their efl'ect upon the health and life of man. 

Sanitation is the sum total of practical measures 
undertaken for the preservation of public health. 

Sanitary art is the practice of public hygiene, the 
erection of public works for the improvement of pubhc 
health. 

Sanitary laiv or public health law or State medicine 
are terms applied to the rules, regulations, and laws 
prescribed by States or municipalities for the conduct 
of individuals and communities, with the aim to pre- 
serve and promote public health. 

Foundations of Modem Hygiene. — Modern hygiene is 
based principally upon three sciences: sanitary science, 
bacteriology, and vital statistics. 

Sanitary Science. — Men have known their depen- 
dence upon the soil upon which they dwell, the air 



FOUNDATIONS OF MODERN HYGIENE 19 

which they breathe, the water which they drink, tlie 
food which they eat, tlie houses in whicli they hve, 
and the many other external factors by which their 
Ufe and w^ell-being are so profoundly influenced. It 
is scarcely more than three score years, however, since 
sanitary science, the science of the environmental fac- 
tors, has been firmly established and the direct causa- 
tive influence of the various external factors has been 
fully shown. Chadwick, Farr, Pettenkoffer and others 
were the first to study the effects of soils, waters, 
foods, clothing, and the general environment of man. 
Only when the influence of these factors had been 
demonstrated could hygiene enter the rank of modern 
sciences. 

Bacteriology. — The greatest impetus toward the 
establishment of modern hygiene has been given by 
bacteriology. Pasteur, Koch and a host of other 
investigators during the nineteenth century have dis- 
covered the hitherto hidden causes of many diseases 
which were destroying innumerable human beings. 
These discoveries of the germs causing disease have 
made possible the prevention of disease and the pro- 
longation of the human life by the study and discovery 
of proper means of fighting the destructive agents of 
disease. 

Vital Statistics. — Hygiene is based on vital statistics. 
Vital statistics may be termed ''public health book- 
keeping." As in economic and financial undertakings 
it is impossible to determine the exact state of affairs 
and progress without a system of bookkeeping, so it 
would be impossible without such a system to determine 
the state of public health, its decline and fall, or rise 



20 ISTRODL'CTIOX TO THE STi'DY OF IIYCilEXE 

and j)ro^ress. By the means of vital statistics the num- 
i)er of persons of various ages, sex, nationaHty, etc., 
living in a given period in a given ])lace may be deter- 
mined, and the actual and natural increment of popu- 
lation, the hirth-rate, marriage-rate, death-rate, etc., in 
a given year, j)eriod, or locality may he learned. 

Vital statistics also show the general morbidity- 
rates, the rates of sj)eciiic diseases, the })robable 
duration and the cxpecUitUm of life. 

Since vital statistics have become an established 
science among ci\ iH/cd nations, the waste of human 
life from the various causes and the ])r()gress of sanitary 
endeavor by the ett'orts of personal, municipal, and 
jniblic hygiene have become evident. 

Conservation of Human Resources. — The function of 
hygiene is the conservation of human resources and 
the prevention of the waste of human life, of w^hich 
there is still a lamentable and deplorable waste from 
preventable causes. 

Upon examining the recorded causes of death in any 
given community, it is found that only a very small 
percentage of deaths (less than 2 per cent.) is due to 
old age. The other 98 per cent, of all deaths are 
caused by disease and pestilence, by violence and war, 
by sin and crime. 

Hundreds of thousands of innocent infants and 
children are still killed, crippled, and maimed by 
infectious diseases. The lives of thousands of adults 
are still being destroyed by typhoid, tuberculosis, 
and many other diseases of adult life. Pneumonia, 
nephritis, and other constitutional diseases are still the 
causes of innumerable deaths. Many, if not all, of 



CONSERVATIOX OF IH'MAX h'KSOCRCI'JS 21 

these are largely prevental)le. (ireat as is the waste 
of human life at present, it is incomparahly less than 
in the past. Great sanitary progress has been made 
during the last and present centuries. The average 
length of life has been considerably lengthened, the 
mortality-rates have decreased, and many diseases 
which W'Cre among the worst enemies of mankind have 
either entirely disappeared or their ravages have been 
materially lessened. 

The length of life has increased over 100 per cent, 
during the last few centuries, the progress having 
been greatest during the nineteenth century. During 
the sixteenth century the average length of life was 
from eighteen to tw^enty years, during the eighteenth 
century it was a little over thirty years, while at the 
end of the nineteenth century it reached thirty-eight 
to forty years. The general mortality-rate in London 
per 1000 inhabitants in the year 1680 w^as 50; in 
1780, 40; in 1905, 15.1. In Berlin the rate from 1751 
to 1780 was 39.34 per 1000 inhabitants; from 1841 
to 1870, 28.78; from 1871 to 1900, 26.22. In urban 
America (white) this rate from 1804 to 1825 was 24.6; 
from 1826 to 1850, 25.7; from 1864 to 1875, 25.4; 
from 1876 to 1888, 22.9; and from 1889 to 1901, 21. 
In New York the rate was 25.99 in 1886, 16.52 in 
1908, and less than 12 in 1916. 

There has been a great reduction in the mortality 
from certain diseases like smallpox, yellow fever, 
diphtheria, cholera, typhoid fever, and malaria. Dur- 
ing the eighteenth century 50,000,000 people died of 
smallpox in Europe; in 1900 there were but 3500 
deaths from it in the United States. 

Since 1793 the United States has had 500,000 cases 



22 INTRODUCTION TO THE STUDY OF HYGIENE 

of yellow fever, resulting, it is estimated, in about 
100,000 deaths. Since the discovery of the species 
of mosquito which transmits the causative factor, 
and the practical preventive measures to which this 
has led, the cases of yellow fever have been greatly 
reduced. In Havana there were 4420 deaths from 
this cause in the eight years from 1891 to 1898, while 
in the eight years from 1899 to 190G they numbered 
but 4G5.1 

The reduction of the mortality-rate from typhoid 
fever has also been great but not yet as marked as 
that of yellow fever, cholera, and smallpox. 

The Main Causes of Disease. — A preliminary announce- 
ment with reference to mortality in 1915, issued by the 
Bureau of Census, indicates that nearly one-third of the 
909,155 deaths reported for that year in the "Registra- 
tion Area" which contained approximately 67 per cent, 
of the population were due to three causes — heart 
diseases, tuberculosis and pneumonia; and nearly 
two-thirds were due to twelve causes — viz., cardiac 
diseases, tuberculosis, pneumonia, nephritis, cancer, 
apoplexy, intestinal diseases, arterial diseases, diabetes, 
influenza, diphtheria and typhoid fever. 

Further Possible Prevention of Disease. — ^Though much 
has already been accomplished in the prevention of 
disease and in conservation of human life, a great 
deal more may be done by proper sanitary measures 
and hygienic control. 

According to the calculations of Professor Fisher, 
*'the length of life could easily be increased from 
forty-five to sixty years, a prolongation of fifteen years. 
This would result in a permanent reduction in the 

^ Report on National Vitality. 



ROLE OF THE NURSE IN PROPHYLAXIS 23 

death-rate of about 25 per cent. The principal reduc- 
tions would come from the prevention of infantile 
diarrhea and enteritis (over GO per cent.), broncho- 
pneumonia (50 per cent.), meningitis (70 per cent.), 
typhoid fever (85 per cent.), tuberculosis (75 per 
cent.), deaths by violence (35 per cent.), pneumonia 
(45 per cent.), so that the estimate of fifteen years' 
prolongation of life is a safe minimum without taking 
into account possible future discoveries in medicine 
or the cumulative influence of hygiene." 

The Role of the Nurse in Prophylaxis. — x\mong those 
combating disease and death there are few whose 
work is so far-reaching and whose endeavors are so 
valuable, or whose work is as important in prophyl- 
axis as that of the nurse. Since Florence Nightingale 
had demonstrated the need and value of the nurse in 
war, an even more emphatic demonstration has been 
rhade of the nurse's value in peace. Not only as an 
aid to the physician, but also by her own work in 
prophylaxis, has she become one of the most impor- 
tant conservators of human life, and her role in the 
prevention of disease and premature death cannot be 
overestimated. 

Within a comparatively short time the number of 
nurses in the Ignited States has been increased to many 
thousands. At present the nurse is found not only 
at the sick-bed in the individual home, but also in 
the tuberculosis clinics, in factories and workshops, 
in department stores, in tenement-house departments, 
health departments, and in a great many private 
as well as public institutions. There is no doubt that 
her field of work and usefulness will be still further 
expanded until it will embrace all human activities. 



CHAPTER II. 
THE HYGIENE OE HABITATIONS. 

Among the factors of external environment there 
are few which play so important a role in the life of 
man as his habitation. Ilonsing conditions are power- 
fnl factors in the ])reservati<)n of human life and the 
j)reventi()n of disease. 

There is an intimate relation between the disease 
and death-rates of populations and the conditions of 
their housing. The density of population in areas and 
localities, congestion and overcrowding in houses and 
many other factors directly influence the health of 
the population. 

The house plays also an important role in the safety 
of its inhabitants, while the proper fire protection of the 
house is a direct factor in the elimination of dangers of 
fires to life and limb. 

The diseases which are associated with housing con- 
ditions are those due to transmission by the bites of 
insects and parasites, those due to the emanations of 
gases and also those due to bacterial origin. Bron- 
chitis, influenza, tuberculosis and pneumonia are dis- 
eases closely associated with housing conditions. 
Several diseases due to intestinal bacteria, such as 
typhoid fever, dysentery, cholera and hookworm dis- 
ease are often associated with defective conditions 



SAFETY AND FIRE PROTECTION 25 

ill houses which ftuor the traiisiiiissiou of infective 
bacteria and dissemination of disease. 

Improvements in housinj^ conditions, the decrease 
of density and congestion, prevention of overcrowding, 
improved fire protection, better Ughting and ventila- 
tion of houses, improved sanitary conveniences and 
comforts, have always led to better health conditions 
of the population. 

The important factors in housing conditions which 
will be briefly discussed are the following: Safety and 
fire protection, light and illumination, air and ventila- 
tion, heating, water supply, disposal of sewage, plumb- 
ing and disposal of house wastes. 

SAFETY AND FIRE PROTECTION. 

The safety of house and inhabitants depends upon 
the proper construction of the house. Houses must be 
constructed of proper materials in a workmanship 
manner in order to prevent accidents due to insecure 
walls, falling plaster from ceilings, tripping over bad 
stairways and other accidents so frequent in badly 
constructed houses. 

Loss of life or dangers to life and limb from fires in 
houses may be prevented by building houses of fire- 
resisting and fireproof materials and by the provision 
of am])le exits to enable the inhabitants to escape from 
the house during fires or panic. The necessity for con- 
structing houses of many stories in densely populated 
cities has led to the increase of dangers from fires in 
multiple dwellings and tenement houses. Progressive 
housing legislation demands the construction of houses 



26 HYGIENE OF HABITATIONS 

of fireproof materials, the enclosing of all shafts, snch 
as elevators, dumbwaiters, etc., by fireproof partitions 
provided with self-closing fireproof doors. In practi- 
cally all modern cities the construction of frame 
dwellings has been prohibited in the city area. 

Exit in case of fire is provided for by means of wide, 
properly lighted, fireproof stairways and also by the 
construction of special fire escapes outside of the build- 
ing, which serve as an exit in case of emergency. 

Fire escapes are constructed of iron and consist of 
balconies in front of one or more windows in each 
apartment, these balconies on each floor being connected 
with iron stairways facilitating the descent of the 
inhabitants of each floor to the ground or their ascent 
to the roof by means of goose-neck ladders. 



LIGHT AND ILLUMINATION. 

Natural Light. — Sunlight is essential to the growth 
of animal and vegetable life; it acts beneficially upon 
health, stimulates the metabolism of the body and 
assists in the oxygenation of the blood. Sunlight is 
also a powerful germicide and disinfectant; it kills low 
organisms, fungi, and moulds, is capable of destroying 
tubercle bacilli within a short time, and is therefore 
indispensible in human habitations. Habitations with- 
out direct sunlight are damp, cold, and unhealthy. 

The amount of natural light within a house depends 
on: 

1. The location and aspect of the house. 

2. The sources of light. 



LIGHT AND ILLUMINATION 27 

3. The location and size of the openings through 
which is penetrates. 

4. The character of windows and of surface within 
the house. 

Direct rays of the sun give more Ught than re- 
flected lights from adjacent surfaces, walls, trees, etc. 
Greater light is obtained through horizontal openings 
on top of the house than from windows in vertical 
walls. 

The intensity of light within a house depends also 
upon the character of the window glass. There is a 
loss of light of 50 per cent, through milk glass, 10 per 
cent, through double glass, and 8 per cent, through 
plate glass. Prism or ribbed glass, by distributing and 
reflecting the rays of the light evenly through the 
room, increases the amount of light. 

The window area of a room should not be less than 
10 per cent, of the floor area; one square foot of glass 
surface should be allowed for every 70 cubic feet 
of interior space. Piers between windows should be 
narrow; window tops should extend to the ceiling, or 
at least to within 6 inches of it. Plate glass is best 
for transmission of light, unless prism glass is used. 
Smooth, light, or light colored surfaces of inner walls 
and floor and ceilings increase the amount of reflected 
light. 

Artificial Light. — Artificial illumination in the house 
is obtained from tallow and paraffin candles, oil or 
alcohol lamps, water-cooled or acetylene gas, and from 
electricity. The value of artificial illumination depends 
upon its source, quality, intensity, heat production, 
impurities generated, safety and cost. 



28 HVaiEXK OF IIABITATIOXS 

The best light is that obtained from electrie eurrent 
through tiingsteu lanii)s. 

Acetylene gas may i)ro(ln('e a very intense and 
brilliant light of from 20 to UiO candle power. The 
intensity of other lights depends on their material, 
the character of the burners, etc. Welsbaeh lights 
are made of mantles impregnated with earthy silicates, 
which become incandescent upon slight heating. 
They give from (>() to 120 candle power. 

All illuminants, except electricitx-, ])ro(luce nuich 
heat and give oH' some impurities, such as carbon 
monoxide, carbon dioxide, sul})hur compounds, am- 
monia compounds, smoke, soot, and moisture. 

Acetylene Gas. — Acetylene gas (C2H2) is produced 
by mixing water with calcium carbide, and during 
this process much heat is exohed. Special generators 
are manufactured for the production of the gas, and, 
contrary to the current opinion, there is little danger 
from explosions, as calcium carbide is not explosive 
either by heat or by concussion. The pipes used for 
ordinary gas illumination may also be used for acety- 
lene lights, but the openings of the tips of the burners 
must be smaller. The light is intense, steady, white, 
and cheap, and is well adapted for houses in rural com- 
munities or wherever there are no central plants for 
the manufacture of electricity or coal gas. 

Coal Gas. — Coal gas is made by heating bituminous 
coal in air-tight vessels. During this process the 
compounds of hydrogen and carbon are transformed 
into other gaseous and solid products. The refined 
gas contains about 50 per cent, of hydrogen, 35 per 
cent, of marsh gas, 6 per cent, of carbon monoxide, 
and 9 per cent, residue. 



LiailT AND ILIA'MIXATIOX 29 

IVater Has. — Water gas is manufactured from 
anthracite coal, steam, and petroleum by a compli- 
cated process. The refined product contains 80 per 
cent, of carbon monoxide; 35 per cent, of hydrogen, 
20 per cent, marsh gas, and 15 per cent, residue. 

Because of the greater amount of carbon monoxide, 
water gas is more dangerous to life and health than 
coal gas. The inhalation of even small amounts of 
water gas is injurious. Large amounts may become 
fatal because the carbon monoxide combines with 
the hemoglobin of the blood and forms an insoluble 
compound. 

Coal gas and water gas are manufactured in central 
plants, from which they are conducted through iron 
tubes and pipes under the streets into houses, and 
through a network of smaller iron pipes throughout 
the houses. The gas-service pipes are made of best 
wrought iron with malleable iron fittings. The house 
service should be provided with main and secondary 
stop-cocks, and meters to measure the amount of gas 
consumed. 

The gas-service system must be perfectly air-tight, 
should be exposed and readily accessible, and should be 
tested for air-tightness by appropriate tests before use. 

Gas fixtures are of various shapes and values. The 
intensity of illumination greatly depends on the char- 
acter of the burner. Argand and Welsbach burners 
are the best. 

Too intense or too brilhant light, causing glare, may 
be the direct cause of serious afl'ections of the eye. 
For the prevention of glare, lamps should be provided 
with proper shades, globes, etc. 



30 HYGIENE OF HABITATIONS 

AIR. 

Air is a compound gas, a mixture of several gases. Its 
chemical composition is as follows: Nitrogen, 78.09; 
oxygen, 20.94; argon, 0.94; carbon dioxide, 0.03; with 
traces of other gases, helium, kryton, neon, xenon, and 
hydrogen. 

The quantity of nitrogen is constant, while the 
quantities of oxygen and carbon dioxide vary accord- 
ing to difYerent conditions. In the outside air the 
variation of carbon dioxide is between 0.03 in the 
very purest mountain air to 0.04 in the air of city 
streets. The amount of oxygen does not vary much 
in the outside atmosphere. 

Air, like all gases, diffuses itself through space, and 
its weight is due not only to its chemical constitutents, 
but also to its physical condition, especially to its tem- 
perature and humidity. The lower the temperature of 
the air, the heavier it is. Warm air is lighter than 
cold air. As the temperature of the air at some places 
is much lower than at other places this difference 
causes variations in weight and produces a general 
motion of air through space, a motion which is often 
perceptible, and when rapid, is known as wind. 

Air also contains a certain amount of water in the 
form of moisture. The amount of moisture depends 
upon the temperature of the air. The higher the tem- 
perature the greater is the amount of moisture that 
the air can absorb. When air is saturated with mois- 
ture, that is, when it contains all the water it can 
absorb, the excess of moisture is deposited in the form 
of dew; it has reached then what is known as the 



AIR 31 

"clew point." The utmost amount of moisture which 
air may contain without reaching the de\v point is 
called absolute humidity. The difference in the amount 
of moisture which air at a given temperature may 
actually contain, and that which it must contain in order 
to reach absolute saturation, is called relative humidity. 

Impurities in Air. — Air may contain certain impurities. 
These may consist of dust of mineral, metal, vegetable, 
or animal origin, or of various gases, the most common 
of which are carbon dioxide (CO2), carbon monoxide 
(CO), etc. There are many sources of these impurities, 
such as artificial illumination, artificial heating, dust 
matter from outside or from the inside of the house, 
dust and debris from the various processes and work 
carried on wdthin the house. Perhaps the most impor- 
tant source is the presence of domestic animals. 

The changes which are produced by the presence 
of human beings are the following: (1) A diminution 
in the percentage of oxygen, (2) an increase in the per- 
centage of carbon dioxide, (3) an increase of volatile 
odoriferous organic products, (4) a possible increase in 
the number of bacteria and microorganisms in the air, 
(5) an increase in the temperature, and (G) an increase 
in the relative humidity of the air in the room. 

Combustion and illumination wdthin the room or 
shop produce changes in the air according to the 
character and source of the combustion, the most 
important changes being the increase in temperature 
and humidity and the addition of certain gases, such 
as (1)2, CO, and others due to the processes of com- 
bustion and illumination. The physical and chemical 
processes going on within the shop add a large amount 



32 HYGIENE OF HABITATIONS 

of dust from the processes iiiiid materials used, and 
sometimes gases and fumes, due to certain chemical 
processes, are produced. 

All these additions to and clianges in the normal 
consistency' of the air are usually regarded as air 
impurities and have a greater or lesser effect upon 
the human i)ciiigs within the confincMl air s})aces. 

The Influences of Impurities in the Air upon the Health. 
— Some of the impurities within the house may have 
no deleterious effect. Others, in the form of dust, 
etc., may become injurious when their quantity is 
too large or when they are of a j)ois()n()us nature. 
Certain germs and bacteria may be found in the dust, 
and other im])urities in the air may also become 
dangerous to health. Of the gaseous imi)urities, car- 
bon monoxide (CO), from leakage of illuminating gas 
or from processes of combustion, is very dangerous, 
as even a small quantity of this gas is poisonous to 
human beings. 

In another place^ I have summarized the present 
opinion on the character and effects of confined air 
as follows : 

1. That confined air in living-rooms and in work- 
shops differs from normal air in the following respects: 

(a) Decrease in percentage of oxygen. 

(b) Increase in percentage of carbonic acid (CO2). 

(c) Persence of certain volatile odoriferous organic 

products. 
{d) Presence of microorganisms and possible pres- 
ence of infectious bacteria. 

1 The Modern Factory — Safety, Sanitation, and Welfare. By 
George M. Price, M.D., p. 162. 



AIR 33 

{e) Frequent addition of dust, gases, and fumes. 
(/) Higher rate of temperature. 
{(j) Increase in amount of moisture. 

2. That ordinary decrease of oxygen as found in 
inhabited rooms and shops probably does not exert 
any deleterious influence on the persons within them. 

3. That an increase in the contents of carbonic acid 
(CO2) from 4 parts to 15 and up to 100 parts in 10,000 
volumes is not dangerous to health. 

4. That it has not as yet been proved that the pres- 
ence of organic matter in confined air has an important 
bearing upon the health of the persons therein, although 
a prolonged breathing of a large quantity of volatile 
malodorous products may be followed by nausea, loss 
of appetite, and general malaise. 

5. That the presence of dust, gases, and fumes is 
extremely dangerous in proportion to their kind, char- 
acter, and quantity and the condition of bodily resist- 
ance of the workers. 

(). That while it is possible that tuberculosis and 
some other bacterial diseases may be due to aerial 
infection, the probability of such infection is not great. 

7. That the ill effects commonly ascribed to impure, 
confined air of ill-ventilated rooms and shops are due 
not so much to the chemical impurities in the air, but 
to the physical properties, such as increased tempera- 
ture, higher rate of humidity, and stagnation of the 
air surrounding the body. 

(S. That an increase of the temperature of confined 

air in workshops above 70° F., and particularly an 

increase in the wet-bulb reading of the thermometer 

above the same degree, is probably injurious to health 

3 



34 HYGIENE OF HABITATIONS 

if maintained for too long periods, and may cause 
fatigue, lassitude, decreased metabolism, anemia, and 
loss of resistence, predisposing the workers to acute 
and chronic diseases. 

VENTILATION. 

By excluding the outside air by means of walls, 
ceilings, and floors, artificial conditions are created. 
Houses are habitable only as long as some provision is 
made for the exchange of air from the outside to the 
inside, and vice versa. The room air which becomes 
impure must be replaced by a supply of fresh air from 
without. This interchange of air is called ventilation. 

The quantity of air which each individual needs 
de])ends on a great many conditions besides the air 
space within the house and the rate of influx. The 
older hygienists based their calculations on the carbon 
dioxide content and determined the amount at 3000 
cubic feet of air per hour. They regarded the carbon 
dioxide contents of the room air as an index to the 
general purity, and held that whenever it exceeded 
0.06, the room air was bad. The degrees of temperature 
and relative humidity are at present regarded as a more 
important index of the condition of the air in a room. 

Natural Ventilation. — The main factor in ventilation 
is not so much the amount of space in the house as the 
amount of air which enters by various means. Air is 
a gas, and as such rapidly diffuses through the house. 
As most of the materials of w^hich houses are constructed 
are porous, a certain amount of air enters and leaves 
through the walls, floors, and ceilings. A certain 



VENTILATION 35 

amount also passes through the cracks, crevices, and 
other sHght openings which are found in even the 
best-constructed houses, near the windows, doors, 
etc. 

The motion of air due to differences of temperature 
and, consequently, of weight is also an important 
factor in ventilation. The colder outside air tends to 
flow into the house while the warmer, lighter air in the 
rooms tends to flow out of the house. The greater the 
difference in temperature the greater the exchange of 
the air. There is therefore some ventilation in every 
house: (1) through the porosity of the building 
materials and the diffusion of the air through these 
materials, and (2) through various openings due to 
faulty construction, etc. 

Chimneys also contribute largely to the interchange 
of air and form flues through which the warm air 
passes. When the wind blows over the openings of 
the chimneys it creates a suction or aspiration and 
large quantities of air are drawn out. The occa- 
sional opening of doors and windows also serves 
to allow the influx of outside air and the flowing 
out of the room air. The value of windows for ven- 
tilation depends, of course, upon their use. In ordi- 
nary houses, not inhabited by too many persons, these 
means of ventilation may be sufficient for all practical 
purposes. These various methods are grouped under 
the term natural ventilation. 

There are also other means by which a larger and 
more frequent exchange of air is produced. These 
are openings made in the windows, in the walls, in 
the floor, or in the ceiling and the roof. They are 



36 HYGIENE OF HABITATIONS 

termed air inlets or outlets, according to their posi- 
tion. Those at the lower ])art of a room usually 
serve as inlets for the cold air, while those at the 
upper parts usually serve as outlets for the warm 
air. 

Sometimes the ui)per sash of a window is movable 
and tilted so as to allow the air to come in and out, 
or the glass panes are sliding or in the form of mov- 
able louvers, or the whole ghiss ])ane swings on a pivot. 
Circular openings sometimes are made in the glass 
pane and are either left open or fitted with a perfo- 
rated sheet-metal circle revolving with the inflow and 
outflow of the air. The lower sash may also be raised 
and have a board placed beneath, thus allowing the 
air to get in upward through an opening between the 
upper and lower sashes. The walls may also assist 
in ventilation by special devices consisting either of 
perforated bricks, or boxes made to fit in the wall, 
with openings allowing the inflow of air. Such open- 
ings may also be made in the ceilings and roofs. 
There are innumerable devices, all serving as means of 
ventilation in ordinary houses. 

Mechanical Ventilation. — This means removal of the 
air from the room or introduction of air into the 
room by mechanical means. The first is called the 
vacuum method, the latter the plenum method of 
ventilation. 

The best method is that carried on from a central 
location and is a combination of the plenum or pro- 
pulsion method with the vacuum or exhaust method. 
The air from the room is exhausted by mechanical 
means and is removed through a system of openings 



HEATING 37 

and tubes, and at the same time fresh ah- from with- 
out is mechanically introduced through tubes and 
openings. 

The advantages of mechanical ventilation are many, 
for they permit control not only of the quantity and 
velocity of the air brought into the room, but also its 
temperature, moisture, and purity. The temperature 
of the air l)efore it is introduced may be regulated by 
passing it over heated or cooled coils. The amount 
of moisture may also be regulated and the dust or 
impurities may be extracted by passage through 
filtering media. Mechanical means of ventilation are 
emploj-ed especially in schools, factories, theatres, and 
other public places where large numbers of persons 
gather within a room. 

HEATING. 

The human body may bear great variations in exter- 
nal temperature providing the change from one extreme 
to the other is not too sudden and providing the equilib- 
rium of the body temperature is maintained by proper 
clothing, food, and muscular exercise. In most parts 
of this country during a large part of the year the 
temperature of the air within the rooms and houses 
would be too low for comfort and health if it were not 
raised by artificial means. There are certain hygienic 
demands for heating houses which may be formulated 
as follow^s: 

1. There must be an equable temperature within 
the house, and the heating apparatus must therefore 
be easily regulated. 



38 HYGIENE OF HABITATIONS 

2. The heating must be continuous so that there is 
no sudden fall of temperature durinj^; night. 

3. The heating should not add any impurities to 
the air in the form of dusts, smoke, or gas. 

4. The temperature of the room should be between 
58° and 70° F., with a relative humidity of 40 to 60 
per cent. 

5. The heating process should be simple and free 
from dangers of explosion, etc. 

G. The heating should be inexpensive and accom- 
plished with as little effort on the part of the dweller 
as possible. 

Means and Methods of Regulation of Temperature. — 
As a rule no attempts are made to regulate the tem- 
peratures of our rooms by artificial means during 
summer. Some lowering of the temperature may be 
gained by preventing insolation, by window curtains, 
blinds, etc., by revolving electric fans, and by opening 
windows and doors. 

The heating of rooms is accomplished by burning 
certain materials called fuels. These fuels are of many 
kinds, such as straw, corn-stalks, dry peat, wood, 
bituminous and anthracite coal, coke, oil, gas, etc. 

Heating may be local or central. In local heating 
the fuel is burned in the room to be heated. In central 
heating the fuel is burned in a central location and 
the heat is conveyed into the rooms by means of air, 
water, or steam. 

Local Heating. — The fuel is burned in special recep- 
tacles, either open, called grates, or closed, called stoves. 

Grates. — The form of radiant heat represented in 
the various open grates is probably one of the oldest 



HEATING 39 

methods of house warming known. A large percent- 
age of the heat, some say 88 per cent., is totally lost. 
The greatest objection, however, is that the heat 
evolved is distributed unequally, that considerable 
drafts are created, and that while a grate fire may 
look cheerful, it is neither comfortable nor adequate. 
There are improved forms of grates in which a greater 
combustion of fuel is accomplished and some of the 
objections to open grates are overcome. 

Stoves. — Stoves made of brick or glazed tile are ex- 
tensively used in European countries. In the United 
States cast- and wrought-iron are used almost exclu- 
sively. Iron heats and cools very rapidly and is apt 
to become overheated. The use of stoves is often 
very convenient, but is inevitably accompanied by 
ashes and dirt, and the need of carrying coal and wood 
to the stoves. The air of rooms heated by ordinary 
stoves is apt to be overdry and overheated. 

Heating with Gas. — Gas is a good fuel for heating 
rooms and houses. Gas stoves must be provided with 
flues leading to chimneys for the disposal of odors and 
gases from the stoves. 

Electricity. — This is an ideal method of heating, the 
only objection against which is its cost. 

Central Heating. — The central heating of small 
dwellings by means of hot-air furnaces is very exten- 
sively used in the United States. As ordinarly made 
the hot-air furnace is a stove, usually placed in the 
cellar and enclosed by a sheet-metal jacket at some 
distance from the stove. The space between the stove 
and the jacket contains air, which is brought from 
the outside of the house by a tube or cold-air box. 



40 H Yd EXE OF HABITATIONS 

This air within the jacket is heated h\ the coal in the 
stove, and, rising, is con(hicted by means of sheet- 
metal pipes or ducts into the various rooms of the 
house. The cold-air box should be made of metal 
and its entrance screened to prevent the introduction 
of dust. The hot-air ducts should be am})le and have 
as few bends as possible. The advantages of hot-air 
furnaces are their low initial cost of installation, the 
absence of radiators occui)ying s])ace within the room, 
and the improved ventilation by the introduction of 
warm air. The objections are that they often })roduce 
• superheated air which is too dry and that the air often 
contains dust, coal gas, and smoke. 

Hot-water Heating. — In this most simple form of 
heating a water receptacle is heated in a central 
location within the house, usually the cellar. This 
receptacle is connected with an ascending pipe leading 
to the upper part of the house, whence a descend- 
ing pipe returns the water to the original receptacle 
below. In each room there may be several coils of 
pipe radiators connected with the ascending or descend- 
ing pipes. The water in the receptacle or heater rises 
and circulates through the ascending and descending 
pipes and radiators. The temperature of the water 
in the system is never very high and is below^ boiling- 
point. The heat may be kept up continuously. This 
is the best system of house heating, especially for 
houses not above three or four stories in height. A 
hot-water system of heating costs somewhat more to 
install than a steam-heating plant, but it has the 
advantage of greater simplicity and lesser cost of 
maintenance. 



HE A TING 41 

Steam Heating. — In this system the pipes are filled 
with steam under low or high pressure instead of hot 
water. The steam-heating plant needs expert attend- 
ance, a large consumption of coal, and cannot be well 
regulated so as to give constant heat. As soon as the 
heat in the boilers is reduced below the production of 
vapor the pipes and radiators are suddenly cooled off. 
There is, therefore, usually a marked difference be- 
tween day and night temperatures of steam-heated 
rooms. An annoying concomitant of a steam-heating 
system is the noise and hammering within the pipes 
due to the steam meeting with the condensed water 
from cooled-oft' radiators. This is called ''water ham- 
mer" and is met very often. There are a number of 
different systems of steam heating. 

The advantage of steam heating are that houses 
may be heated with a comparatively small installa- 
tion expense, or even from a central location outside 
of the house, and also that houses of any size may 
be heated to any temperature desired. The objection 
to steam-heating systems are the need of specially 
trained caretakers, the undue heat of the steam pipes 
and radiators, the usual stoppage of steam at night, 
and the comparatively high cost in fuel consumption. 

Temperature Regulation. — The degree of heat in the 
rooms is measured by thermometers; the degree of 
relative humidity or moisture in the air is measured 
by various hygrometers. In houses provided with a 
mechanical system of ventilation and heating the 
temperature of the room may be regulated by thermo- 
stats and the relative humiditv bv humidostats. 



42 HYGIENE OF HABITATIONS 



WATER SUPPLY. 

Water and Health. — Water is essential to human life. 
Nothing in the organic world can exist without water; 
it is a component of everything in the vegetable and 
animal kingdom. Sixty-three i)er cent, of the weight 
of the human body is water. Without water life can 
be sustained only for a very short i)eriod. 

Water is needed not only for drinking purposes, 
but also for cooking the food, for washing the body, 
for laundry purposes, for cleaning utensils, and for 
many other household j)urposes. The quantity of 
water needed for the various household purposes varies 
according to the habits of the individual and the 
degree of civilization. Thirty gallons of water per 
capita per day is a very conservative estimate, while 
a greater supply is beneficial. 

Water, chemically pure, consists of two volumes of 
hydrogen and one part of oxygen. As water is a great 
solvent it is very rarely, if ever, found pure; it con- 
tains various ingredients taken up from the objects 
with which it comes in contact. Some of these are 
harmless, but the presence of others in drinking water 
may be harmful. 

The impurities found in water, which may have 
some influence upon man, may be gases, minerals, 
organic matter, and microbes. The gases are those 
which are a component part of air, oxygen, and 
carbon dioxide. 

Water dissolves most of the minerals with which it 
may come in contact, and among those which may be 



WATER SUPPLY 43 

found in water are the following: chlorides, calcium, 
magnesium, iron, sulphur, and many others. 

The organic matter may be of vegetable or of 
animal origin. Microscopic plants, vegetable fungi, 
detritus of vegetable life, as well as the products of 
decomposition in vegetable life, are abundantly found 
in water. Substances of animal origin found in water 
include minute insects, infusoria, the ova of insects, 
some minute parasites, suspended animal debris, 
products of decomposition, disintegration, and putre- 
faction. 

The most important constitutents of water from 
the hygienic point of view are the microbes or repre- 
sentatives of germ life, bacteria, bacilli, etc. The 
millions of bacteria usually found in water are harm- 
less, as a rule, but there may be some which may 
become a menace to health and life. These germs 
are called pathogenic. They are the causes of the 
specific diseases of typhoid fever, cholera, dysentery, 
diarrhea, and other similar disorders. They get into 
the water by various routes and means, but most 
commonly through pollution with animal sewage and 
decomposed organic matter. 

Besides the impurities enumerated already, water 
may also contain certain poisons which it has dissolved 
during its course over or under the ground. The most 
important of these are copper, lead, zinc, arsenic, and 
sulphur. 

Water and Disease. — The physical impurities, such 
as the debris of vegetable, animal, and mineral matter, 
which are often found in water, may be dangerous 
to health, because of the disturbances they cause in 



44 HYGIENE OF HABITATIONS 

the digestive tract. The degree of (h\iiger depends 
ii})()n the quantity, composition, etc. The chemical 
impurities may be found in the form of dissolved metals 
or gases, and include sulphur, lead, arsenic, and other 
toxic elements in greater or lesser quantities. The 
ingestion of water containing such substances may 
become dangerous to health, according to the amount 
and toxicity of these ingredients. 

Certain parasites and their ova are also found in 
water. Among these are the ova of ta|)e\v()rms, 
roundworms, and especially of hookworms. The ter- 
rible scourge of ''hookworm disease" in the Southern 
States is transmitted by means of water containing 
the ova. 

Typhoid, cholera, and dysentery have been, and are 
frequently caused by the drinking of water containing 
the germs of these infectious diseases. Indeed, these 
have been properly named the '' water-borne diseases." 
The presence of typhoid, cholera, and dysentery geims 
in water, as well as the direct transmission of such 
diseases through the agency of water has been clearly 
demonstrated. There are also abundant data which 
show a marked decrease in the prevalence of such 
diseases whenever precautions for the prevention of 
contamination or for purification of contaminated 
water are taken. 

Good water should be clear, free from sediment 
and suspended matter, colorless, odorless, aerated, of 
a pleasant taste, cool, and soft. Water is judged by its 
palatability, degree of hardness, turbidity, the amount 
and character of organic contamination, the presence 
or absence of metallic poisons, and the number and 



WATER SUPPLY 45 

character of the bacteria present. All palatable water 
is not necessarily wholesome, nor is a water bad 
merely because it may be unpalatable. The taste 
of water depends upon the temperature and upon 
the presence of air and carbonic acid. x\s carbonic 
acid may be due to organic decomposition, water 
may be organically contaminated and still taste 
pleasant; on the other hand, chemically pure dis- 
tilled water has an insipid taste. 

The hardness or softness of the water depends upon 
the presence or absence of carbonate of lime, or of 
the sulphate and chloride. Temporary hardness is 
caused by the presence of carbonate of lime (chalk), 
which is driven off by boiling; permanent hardness 
depends upon the chlorides, sulphates, salts of mag- 
nesium, etc., and cannot be removed by boiling the 
water. Hard water, on boiling^ precipitates the salts 
upon the side and bottom of the vessels, and thus 
prevents the proper cooking and softening of certain 
vegetables; hard water also prevents the formation 
of lather and the dissolving of soap in washing clothes. 
Except for these effects it is questionable whether 
hard water is otherwise injurious. 

Sources of Water Supply. — There are three main 
sources of water supply for habitations: (1) rain 
water; (2) surface water; and (3) subsurface water. 

Rain Water. — Rain water is the purest of all waters, 
unless it is contaminated by the impurities in the air 
during its fall, or by the vessels in which it is stored. 
Rain water is not very ])alatable because of lack of 
aeration, but is very good for cooking and laundry 
work because of its softness, 



46 HYGIENE OF HABITATIONS ' 

The quantity of rain water depends upon the 
amount of the rainfall, the periodicity of the fall, and 
the area of the collecting vessels. As a constant 
source of water sui)i)ly rain water cannot very well 
be depended upon, and in cities in which the surface 
air is apt to be much contaminated, rain water is not 
without dan(i;crs because of the imj)urities -it gathers 
during its fall. In farm houses and rural communi- 
ties the collection of rain water as a su})plementary 
source may be of benefit, j)rovided care is taken that 
the tubs, barrels, tanks, or cisterns wherein it is 
collected are clean, free from impurities, and kept 
covered after the collection of water. 

Hnrjace Water. — Surface waters, like ponds, lakes, 
and streams, are not a very good source for water 
supplies, because they are easily contaminated with 
sewage and other organic materials which are so abun- 
dant upon the soil, especially about or near human 
habitations. They are principally collections of the 
drainage of the very much polluted surface soil and 
may contain any dangerous impurities, like the germs 
of typhoid fever and others. Large and swift rivers 
and very large lakes are sometimes used as a source 
of water supply, but even these are apt to be danger- 
ous unless the water for drinking purposes is taken 
far from the shore or is purified before use. 

Subsoil Water. — A large proportion of the water 
falling upon the ground in the form of rain or snow 
slowly sinks into the soil through its porous strata 
until it finds a stratum which is impermeable. It 
then collects and forms underground water reservoirs 
which are at a greater or lesser distance from the 



WATER SUPPLY 47 

surface, and can be reached by digging deep enough 
into the ground. 

During the process of percolation into the ground 
the water is filtered and loses some of its impurities, 
but in passing through the various soils it may take 
up certain minerals with which it comes in contact 
and these become suspended or dissolved in it. 

The underground water basins lie sometimes at a 
very great depth. The water therein is in constant 
motion in a vertical or horizontal direction, and as 
the pressure is sometimes great the water may crop 
out at some surface in the form of springs. The 
water in such springs, when at a proper tempera- 
ture and free from minerals, is palatable and whole- 
some. Sometimes these springs have considerable 
mineral ingredients dissolved, and are at high tem- 
perature, owing to the character of the earth's crust 
which the water traverses. These are the sources of 
*'hot" or ''mineral" springs. 

The deep-lying underground water may be reached 
b}' driving wells into the ground into the lower imper- 
meable stratum. Water from deep wells of this 
kind is very good. The water from shallow wells or 
those dug into the first near-surface-lying under- 
ground water basin is apt to be impure, because such 
wells usually tap a subsoil water, which is gained by 
surface drainage from localities largely contaminated 
with organic matter, manure, and sewage. 

The privies and cesspools near habitations almost 
always drain their liquid contents into the sources 
from which shallow wells get their water, and many 
epidemics of typhoid and other diseases have been 



48 HYGIENE OF HABITATIOXS 

traced to the use of polluted shallow well water. 
Shallow wells are also called dug wells to distinguish 
them from deep and artesian wells, which are com- 
monly bored or driven. Wells must he dug at con- 
siderable distances from houses and stables, and at 
places where no surface impurities can drain into 
them. They should be lined with brick and cement, 
or with gla/.ed tiles set in cement, and also fitted 
with ])roper covers to ])rcvcnt the falling in of filth 
from the outside. The water is drawn from the well 
in buckets or pails either worked by hand, windlass, or 
by means of suction ])umi)s or other mechanical devices. 

Aqueducts. — For the supply of large towns wdth their 
millions of po])ulation immense water-suppl\' works are 
needed. Their construction and the supervision of the 
water area must be in charge of engineers. 

House-water Supply. — Where there is a town-w^ater 
supply system, houses are supplied from the street 
mains; the size of the street mains depends upon the 
w^ater-pressure and the number of houses to be sup- 
plied. The branch house-water supply pipes coming 
from the street mains should not be less than three- 
quarters inch for small houses and from one and a 
half to tw^o inches for larger houses. The house pipes 
are connected with the street pipe by "corporation 
taps." There should be a stop-cock under the side- 
walk, and also one on the service pipe at the entrance 
to the cellar. Street mains are made of galvanized 
iron; some of the house pipes may be made of lead. 
The materials and workmanship of all water pipes 
must be of the best, and they should be protected 
from freezing w^henever exposed. 



WATER SUPPLY 49 

Whenever the pressure of the street mains is insuffi- 
cient to Uft the water to the height of the upper stories 
of a house, storage tanks or cisterns must be provided 
upon the roof. These tanks are commonly made of 
cedar or cypress wood, are round in shape, and should 
rest upon a solid foundation, preferably upon iron 
beams. When located within the house the tanks are 
metal lined. All tanks should be provided with suit- 
able covers, also with overflow pipes and water- waste 
protecting valves. The overflow may be discharged 
onto the roof, or lead down into the cellar and dis- 
charged into a sewer-connected, properly trapped 
water-supplied open sink. 

In order to lift the water to the highest story some 
mechanical means, such as pumps, driven by gas, 
steam, or electricity, may be necessary. 

Hot-water Supply. — Modern houses are not only 
provided with hot water, but provisions are also 
made to supply the house with hot water necessary 
for bathing, w^ashing, and cleaning purposes. 

The hot-water supply is derived in most houses from 
boilers of copper or iron, connected with the kitchen 
range. In larger houses special hot-water furnaces 
and boilers may be provided, from which the hot- 
water pipes go to every fixture in the house. The 
heating of water by means of electricity is practicable 
wherever there is electric power within the house. A 
simple device to heat water in a vessel is by means of 
an electrically heated metal coil placed in the vessel. 

Purification of Water. — The large amount of impuri- 
ties, some of them ^'ery dangerous to the health and 

life of the consumers, which are commonlv found in 
4 



50 HYGIENE OF HABITATIONS 

drinking water render the problem of water purifica- 
tion an important one from a sanitary stand-point. 
Water purification should be twofold, public and ])ri- 
vate. Whenever the water suppl\' is collective, public, 
and on a large scale, the community at large should 
provide for proj)er water purification. Whether there 
is a ])ublic water-purification plant or not, every 
individual household should provide some means of 
local water purification. 

Methods of Domestic Water Purification. — 
Water may be purified for domestic use by sedimen- 
tation, boiling, distillation, chemical means, and by 
filtration. 

Sediinenfafion. — Water may be freed from its coarser 
particles of impurities of sand and dirt by letting it 
stand in a vessel from twelve to twenty-four hours. 
This may also free the water from such organic matter 
and impurities as are held in suspension, without, 
however, clearing it of the impurities held in solution. 

Boiling. — All living organic matter and germs are 
destroyed by raising the temperature of water to the 
boiling-point and by keeping it at that temperatue 
for a certain time. This is the cheapest and most 
available method of purification, and is also the most 
eflficient. The objection against boiled w^ater is the 
insipid taste which results from the expulsion of air 
and carbon dioxide by the process of boiling. The 
pleasant taste of the water may be restored to boiled 
water by aeration, or by charging it with carbonic acid 
gas. 

Distillation. — ^This is the surest and best means of 
removing all impurities. It kills all germs, including 



WATER SUPPLY 51 

all of the spores, and gives an absolutely pure water 
which when aerated or eharged with carbon dioxide 
is very palatable in addition to being pure. The objec- 
tion to distillation of water for domestic purposes 
lies in the necessity for a proper apparatus; but the 
time seems to be approaching when every house will 
be furnished with water-distilling apparatus just as it 
is at present furnished with a cooking range and hot- 
water boiler. The apparatus to be of value should 
be simple in construction, easily operated, durable, 
strong, and readily cleansible. It should furnish an 
adequate supply of water for all domestic purposes 
with little trouble and at small cost. Such an ideal 
apparatus has not as yet been invented, but there 
are a number of devices which approach it and may 
safely be used. 

Chemical Means. — The settling of turbid water 
may be* hastened by the addition of a few grains of 
alum (not more than six grains to the gallon). The 
addition of small quantities of potassium perman- 
ganate has a destructive effect upon organic matter. 
Addition of tea leaves and other vegetables con- 
taining tannin is said to reduce the danger from 
organic impurities, but this is problematic. Other 
chemicals, like borax and boracic acid, copper sul- 
l)hate, etc., have been advocated, but when used in 
too small quantities they are of little or no value; 
when used in larger quantities they may become almost 
as dangerous to health as the impurities which they are 
intended to destroy. 

Water Filtration. — Water may be purified by 
filtration, /. e., by letting -the water pass through 



52 HYGIENE OF HABITATIONS 

some material which is capable of retaining some or 
all of the contained impurities. The value of a water 
filter depends upon the followin<x factors: 

1. The character of the filtering medium and its 
ability to retain and remove from the water as many 
impurities as possible. 

2. The thoroughness of the ])rocess and its rapidity. 

3. The ready cleansing of the filtering media and its 
ready disinfection. 

4. The simplicity, cheapness, and accessibility of the 
filter. 

It is claimed for some filters that they are able to 
remove all the organic imj)urities from the water, 
as well as the bacteria, but this is not yet proved. 
It is certainly true only of a very few filters upon 
the market, and of those only when they are new. 
Whenever water is suspected of containing patho- 
genic bacteria, dependence upon filters may become 
dangerous to health, and distillation is the only sure 
way of securing purity of drinking w^ater. 

The materials which are used for filtering water 
are sponges, wool, asbestos, sand, stone, porcelain, 
infusorial earth, spongy iron, magnetic carbide of 
iron, charcoal, etc. Sponges, wool materials, and 
asbestos cannot very well be depended upon; at best 
they act but mechanically, easily get dirty, and are 
difficult to clean. Sand and porous stone will arrest 
suspended matter; they may even remove some of 
the organic matter. It is doubtful w^hether all organic 
impurities and microbes can be removed by them. 
Charcoal is a very good filtering medium in some 
respects. Animal and not wood charcoal is used. 



WATER SUPPLY 53 

Animal charcoal is prepared from calcined crushed 
animal bones, and may be used in block form or in 
the form of a powder. Charcoal removes coloring 
matter and considerable organic matter from water, 
but does not remove all organic impurities. Charcoal 
used for filtering must be frequently recalcined. I'n- 
glazed procelain is used for filtering purposes and is 
quite effective in removing Avater impurities, pro- 
vided the filtering porcelain is frequently cleansed, 
as the impurities are apt to become clogged. 

Infusorial earth is used in the Berkefeld filter. 
It is pressed in the form of hollow tubes. The w^ater 
passes under pressure through the fine pores of the 
filter and gains access to the tap. It is claimed for 
this filter that when new it will remove all organic 
matter and bacteria from the water. The filter is 
made in various forms and sizes and may be attached 
the the house-sink faucet. The filtering tube must 
be removed frequently, sometimes more than once a 
day, and the dirt accumulating upon the surfaces 
washed off, otherwise the filtering process becomes 
slower and slower and stops when the pores of the 
tubes become clogged. 

Ice. — The use of frozen water in the form of ice is 
very extensive, and when used for drinking purposes 
there is the same danger of organic impurities as in 
ordinary unfrozen w^ater. 

As most of the ice used is obtained from the surface 
of lakes, ponds, and rivers subject to organic con- 
tamination, the use of ice may become very dangerous. 
It is best to use ice only as a cooling medium, with- 
out melting it for drinking purposes. Ice may be 



54 HYGIENE OF HABITATIONS 

made from distilled or boiled water, and is then free 
from impurities. It has been shown ex})erimentally 
that freezing does not kill the bacteria in the water. 
Ice-chests and refrigerators ha\e become a household 
necessity. They are commonly made of wood, hard 
wood is best, with mineral ])a('king in the double 
wall to insure non-conductivity. Within the refrig- 
erator is lined with metal or ])()r('elain or enamelled 
iron. Some refrigators are kept cold by means of 
electricity without the use of ice. 

The waste i)ipes from the ice-box should never 
connect directly with the plumbing of the house, but 
should discharge into the sewer-connected, properly 
tra})])ed, water-su])])lied, open sink. The waste pipe 
is sometimes provided with flap valve to prevent 
the entrance of warm cellar air. 



HOUSE DRAINAGE. 

Sewage and its Disposal. — One of the most important 
needs in connection with human habitations is the 
disposal of the organic matter and sewage due to 
the presence of the inhabitants. The average adult 
passes about 3 ounces of solid and about 40 ounces 
of liquid excreta, w^hich when multiplied by the num- 
ber of house dwellers forms a large amount of organic 
detritus. This organic matter if left exposed for 
some time begins to decompose and undergo putre- 
factive changes, evolving foul gases and odors during 
the process. The solid excreta may also contain a 
large number of germs, some of which, such as the 



HOUSE DRAINAGE 55 

<];erms of cholera, typhoid, intestinal disease, and 
others, are pathogenic. The organic excreta and 
detritus are embraced under the general term of 
"sewage," and unless there is proper and effective 
disposal they become not only disagreeable and un- 
pleasant, because of the foul odors and gases, but, also, 
at times, dangerous to health and life. 

Methods of Sewage Disposal. — The principal methods 
of ultimate disposal of sewage are the following: 
(^remation, chemical precipitation, land irrigation, 
disposal into rivers, lakes, and seas, and the various 
modern bacterial, septic, and biological methods. 

The immediate disposal of sewage from the houses 
may be dry or by means of w^ater. In isolated houses 
without water supply, and with a few house dwellers, 
the means of disposal of sewage is by pails, earth 
closets, privy vaults, and cesspools. When there is 
a water-supply system the sewage may be carried 
out through a system of plumbing pipes and fixtures, 
and be disposed of in cesspools or through land 
irrigation. 

Pail System. — The pail system is by means of the 
simple expedient of gathering the solid excreta into 
tight pails or receptacles and then removing the 
contents when the pails are full. 

Privy Vaults. — Privy vaults are in extensive use in 
this country, in rural communities, villages, farms, 
and in some cities which are not sewered. There are 
a large number of them in the outlying boroughs of 
New York and the outskirts of other cities. 

The privy vault, as ordinarily constructed, is a hole 
in the ground, over which there is a raised platform 



56 HYGIENE OF HABITATIONS 

with a seat, the wliole e()\'ere(l with some sort of a 
shed. The })rivy is ahvays a iiuisauee, beeause of its 
proximity to the house, of the foul o(h)rs emanat- 
ing from it, the flies and insects it attracts, the 
contamination of surrounding soil, and the ])ossil)l(^ 
pollution of near-lying wells and water courses. 

This pollution of the water and of the soil is the 
greatest objection against ])rivy ^•aults. These i)rivies 
remain in the same place so many years that the 
soil beneath them becomes a veritable sewage lake 
frpm which contamination of the surrounding soil and 
of the water supi)ly nearl)\' results. The diseases 
which may be due to such soil pollution are typhoid 
fever, hookworm, dysentery, tapeworm, etc. In the 
South the terrible ravages of the hookworm disease 
are due mainly to soil pollution and unsanitary privies. 

The principal parts of a privy are the shed, the 
seat, and the receptacle into which the excreta are 
dropped. The shed in a sanitary privy should be 
made of tightly fitted V)oards, with windows properly 
screened and doors well closed in order to prevent 
insects and flies from gaining access. The seat should 
be so arranged as to be convenient for use, and should 
be free from contamination of excreta. The receptacle 
or the place into which the excreta are dropped should 
be more than a mere hole in the ground, from which 
the liquids percloate into the surrounding soil, and in 
which the excreta remain and decompose; it should 
be made w^ater-tight by being lined with cement or 
some non-absorbent material. The excreta when 
dropped into this w^ater-tight receptacle will remain 
there and must be removed from time to time. A 



HOUSE DRAINAGE 57 

still better method is to place in such water-tight 
receptacles a tight portable pail which is hung on a 
hook from the seat. The excreta are dropped directly 
into the pail, which may be removed as soon as it fills, 
and the contents cremated or disinfected, the pail 
cleansed, washed, and disinfected, and returned to 
its place. For the purpose or removing these pails 
and cleaning the vault beneath the privy each part 
of the privy should be made with a sling cover so as 
to be accessible. 

Cesspools. — These may be used when the house is 
provided with fixtures and pipes to carr}' the sewage 
out, and to collect it in a cesspool at a point distant 
from the house. The so-called "leeching" cesspools, 
which are not water-tight and allow liquids to drain into 
the ground, are open to the same objections as privy 
vaults. When cesspools are water-tight, they must 
be emptied at periodical intervals or provided with 
automatic ejectors and siphon apparatus to discharge 
their contents. The best mode of discharge is by 
means of a system of intermittent filtration, or subsoil 
irrigation. The sewage is emptied into earthenware 
pipes with open joints, which lies several feet under 
ground and radiate in different directions, through 
land to be irrigated. The liquid sewage drains into 
the ground at the joints and is effectively disposed 
of, enriching the land. 

The Water-carriage Method. — This method is now 
extensively used in cities and towns where sewers 
are built. It is the best means of disposing of the 
liquid and sewage contents of houses and streets. 
The sewage from the sewers is either collected and 



58 HYGIENE OF HABITATIONS 

led to the ultimate disposal works, or is carried into 
the sea and water courses. 

There are two methods of sewering houses by water 
carriage. In the comhincd method not only sew'age 
proper is carried away through the ])lumbing pipes 
and the street sewers, but also all other waste waters, 
and especially all rain water collected from the roofs. 
In the separate system the rain water is disposed of 
by means of separate pipes, and the sewers proper 
carry away only the liquid and solid waste matters 
from the house itself. In the separate system the 
pipes are smaller, and thus decrease the expense of 
the plumbing; on the combined system the pipes 
must be large enough to discharge the sometimes 
enormous amounts of storm water. The combined 
system is the one used more extensively. 

Street sewers are constructed by the municipalities 
and are made of brick, earthenware, and iron. Every 
house connects with the street sew^er by separate 
house sewers. 

PLUMBING. 

Materials. — The plumbing system of the house 
consists of receptacles (or as they are termed ''fix- 
tures") which receive the various forms of house 
waste, and of pipes connected with these fixtures, by 
means of which the waste matter is carried into the 
street sewer. As the pipes carry w^aste water and at 
times considerable quantities of gas, the materials 
from which the pipes are manufactured must be 
strong, durable, and water- and gas-tight. 

The earthenware or "clay" pipes which were for- 



PLUMBING 59 

merly cxt(Misively used for house drains and liouse 
sewers are objectionable. They are obsolete now, 
and most munici{)alities have prohibited their use 
within the house and limited them to the short lengths 
needed for house sewers, outside of houses, w^hen they 
are laid on rocky or solid ground. The onl}^ advantage 
of earthenware is its cheapness; but, on the other 
hand, its brittleness is such that it is impossible to 
make gas-tight drains to withstand any long and con- 
stant use. Earthenware house drains are veritable 
channels of filth, emitting foul and offensive odors. 

Lead. — ^Lead is quite extensively employed in the 
manufacture of piping. It has some advantages in its 
ductibility, but the pipes are heavy, expensive, and 
easily injured by nails driven into them, by being 
gnawed through by rats, etc. The use of lead is 
limited to short lengths of pipe, to branch waste 
pipes and to small-caliber water pipes. 

Iron. — The material which is almost universally 
used for pipes is iron; it has all the advantages of 
cheapness, hardness, durability, and tightness. 

Brass. — Brass, nickel, and other hard-metal pipes 
might be used were it not for the expense. Glass is 
a good and appropriate material for piping, and when 
its manufacture is perfected it will probably be used 
extensively. 

Joints. — The proper joining of the several lengths 
of pipe used in the house is of great importance, 
as otherwise the system cannot be made gas-tight. 
Earthenware pipes are joined by means of cement. 

Lead pipes are joined by means of solder-wiped joints. 
Cast-iron pipes are joined by means of lead-calked 



60 HYGIENE OF HABITATIOXS 

joints. Wrought-iroii and brass pi])es are joined by 
screw joints. Lead })i])es iwo joined to iron ])ipes by 
means of })rass ferrnles. 

Pipes. — Tlie plumbing system within the house 
consists of several pipes — vertical and horizontal. 

Vertical Pipes. — The vertical pij)es are the fol- 
lowing: 

The Rain Leader. — This carries down the rain water 
from the roof into the house drain. 

The }]\iste ri])e.— This carries down the waste water 
from kitchen sinks, wash-basins, laundry tubs, etc. 

The Soil Pipe. — This is connected with the water 
closets and, usually, with the bath tubs, and carries 
down the sewage and waste from these. 

Horizontal Pipes. — The House Drain. — This is the 
principal horizontal pipe. It connects with all the 
vertical pipes and carries away the whole house-waste 
matter into the street sewer. 

House Sewer. This name is applied to the short 
length of drain a few feet outside of the house founda- 
tions which leads to the connection with the street 
sewer. It is really a part of the house drain. 

Sizes. — The sizes of the various pipes should corre- 
spond with the amount of waste matter they are 
supposed to carry. There is no advantage in making 
the pipes too large; smaller pipes are apt to be better 
flushed than larger pipes. A two-inch waste pipe with 
only two or three fixtures attached to it ought to be 
sufficient for a private dwelling. The New York rules 
require a four-inch pipe in tenemant houses where 
five or more sinks are used. Three- and four-inch 
soil pipes are adequate in private dwellings; five-inch 



PLl'MBIXG (il 

pij)es are required in tenemaut houses with five or 
more water ch^sets. Branch waste pipes vary from 
one and one-half inch for basin and laundry tubs to 
two-inch pipes for other fixtures; branch soil pipes 
should not be less than four inches in diameter. 
House drains and house sewers are from four to six 
inches in diameter, according to the number of 
fixtures in the house. The six-inch drains, invariably 
demanded by municipal authorities, are sometimes 
entirely too large to be properly flushed. 

Sewer Air. — The materials of which pipes are made 
should be perfectly water-tight, to prevent any leak- 
age of the sewage and waste fluids. The pipes should 
also be gas-tight, because the gases generated within 
the pipes are believed to be imdesirable for the inhabi- 
tants of the rooms in which the plumbing pipes are 
situated. 

The plumbing system connects the house with the 
street sewer, and the same pipes which serve to rid 
the house of liquid waste and sewage matter become, 
reciprocally, a direct means of entrance for the air 
and gases in the street and house sewers to the house 
and rooms. Is this desirable? 

There is still a great deal of misapprehension of the 
common terms sewer gas and sewer air. The popular 
idea of sewer gas is that it is a distinct gas, some- 
thing like illuminating gas, which is found only in 
sewers and ])lunil)iiig ])ipcs, and that its inhalation is 
harmful to a great degree. There are some, indeed, 
who believe that sewer gas is capable of producing 
certain diseases like typhoid fever, diphtheria, etc.;' 
and not so long ago a prominent sanitar\' inspector 



62 HYGIENE OF HABITATIONS 

asserted that she traced several cases of tuberculous 
meningitis to defective pipes under sinks. The theory 
that sewer gas causes various diseases was once up- 
held by noted sanitarians, and seriously advocated by 
Drs. Shnon, liichardson, (iorfield, and others equally 
prominent. 

As a matter of fact, later research has shown that 
there is no such gas as sewer gas. What is termed 
sewer gas is but sewer air, and there is no more reason 
to term the air in a room ''room gas" than the air of 
sewers "sewer gas." The sewer air may at times be 
as pure, and more so, than the air of rooms, and, at 
other times, it ma\' contain the same or more impurities 
than room air. 

The impurities ordinarily found in sewer air are an 
excess of carbon dioxide, carbon monoxide, illuminat- 
ing gas, sulphuretted hydrogen, marsh gas, ammonia, 
and other gases found wherever decomposition and 
putrefaction takes place; there may also be found a 
large number of bacteria and various microorganisms. 
This composition of air which at times may be found 
in sewers, while not liable to directly cause various 
diseases, is certainly not desirable as an additional 
mixture to the air in our rooms, air which, without 
any additions, is rich in impurities. There is no 
doubt that the inhalation of impure sewer air is inju- 
rious to human beings, in the same manner as is the 
inhalation of any impure air, and therefore it is impera- 
tive to prevent the incoming of air from sewers into 
the house and rooms. 

Traps. — As there is a direct connection of the rooms 
with the sewer in the house-plumbing system, the 



PLUMBING 63 

problem is how to disconnect the house from the 
sewer and at the same time leave the plumbing system 
to perform its functions? 

The problem is solved by means of traps. 

A trap is a bend in a pipe, so constructed as to 
retain a certain amount of water. This water is called 
seal, and serves as a barrier to the backflow of air 
from the sewer into house pipes. Traps are espe- 
cially constructed in them, and thus cut off communi- 
cation between sewer and house. 

The house is disconnected from the sewer by the 
main trap on the house drain. This serves as the prin- 
cipal barrier to the inflow of sewer air into the house, 
but there are also additional traps on the branch 
pipes under each and every fixture which serve to 
prevent the bad air in the house pipes from coming 
into the room from and through the fixtures. Thus 
there are a main trap, the house-drain trap, and a 
multitude of fixture traps. The traps are made in 
various forms, and have innumerable names and 
shapes, but all are intended to serve the same purpose. 
There are also a number of mechanical traps with 
various devices for strengthening the action of the trap 
as a seal. Of course, as everywhere in plumbing, the 
simpler the contrivance the better it is. The most 
commonly used traps are the "running trap" on 
house drain and the "S" traps on fixtures. 

Loss of Seal. — ^The traps can be depended upon 
only as long as their seal, i. e., the water in them, is 
intact; but if, for any reason, this seal is broken or 
"lost," it is evident that the trap becomes useless. 
There are a number of causes, such as evaporation, 



G4 IIYGIEXE OF HABITATIONS 

momcntuni, capillary attraction, siphona^c, and, })cr- 
liaps, hack pressnre, throu^i:!! whicli a trap may lose 
its seal and thus become inett'ective as a harrier to 
sewer air. 

Loss hif Kvaponttion. — The water in a trap may 
evaporate if the fixture over the trap is not used for 
a lonii: time; hence, house dwellers may find the 
houses they left for the summer full of had air on 
their return, ()win<j to the loss of seal. This evapora- 
tion can only l)e prevented by frequent use of the 
fixture, or by filling in the traps, before leaving and 
closing up the house, with some oil or other non- 
evaporable material. 

Loss by Momentum. — Loss of seal by momentum 
is due to negligence in pouring into a fixture a large 
amount of water, suddenly and forcibly, so that the 
momentum is insufficient to empty the trap as well. 
This can be prevented only by care. 

Loss by Siphonage. — A more important loss of seal 
occurs through siphonage. The water in the trap or 
seal is suspended between two columns of air, and is 
influenced by any and all currents of air on either 
side of the seal. A discharge of water from a large 
fixture connected with a vertical pipe acts like the 
drawing of a cork or piston through the pipe, i. e., it 
creates a vacuum behind it, causes great suction, and 
draws out, or "siphons" out, any water which may 
be in the trap. 

By "siphonage" is therefore meant the emptying 
of the seal of the trap by the aspiration of the water 
in the trap as a result of the downward rush of water 
in the pipes with which the trap is connected. 



PLUMBING 65 

The siphoning of traps is a frequent occurrence in 
large houses in which the water from fixtures in the 
top floors has a distance to travel and falls with great 
momentum. Every discharge of a water closet on a 
top floor will siphon out the seal of the traps of sinks 
and wash-basins on the lower floors. 

Loss by Back Pressure. — This happens in house- 
drain traps during big rain storms when the street 
sewers are overflooded, and part of the overflow 
backs up into house drains where it may force 
back the water of the main trap. It may also 
occur during a rise of tide in houses near the shore. 
What is ordinarily understood by back pressure, 
however, is the absorption of foul gases by the water 
in a trap from the air in the pipes. As the water 
is exposed continuously to the gases in the pipes 
this absorption goes on all the time, and thus the 
gases may enter the room through the water in the traps. 

Vent Pipes. — The prevention of the siphonage of 
traps, as well as of the back pressure, has occupied the 
minds of many plumbers, and various means have 
been employed to remedy the evil. A number of 
mechanical traps have been invented, but they all 
have the one fatal defect, that they are cumbersome 
and do not prevent the evil they intend to remedy. 

Actual backing up of water in main traps can be 
prevented by the tide valves. There are a number of 
these on the market, and most of them serve their 
purpose well. 

The back })ressure, which consists of the absorption 
of gases by the water in traj)s, can very well be pre- 
vented by a good ventilation of the pipes. This is 
5 



66 HYGIENE OF HABITATIONS 

readily accomplished by the ordinary extension of the 
vertical pipes above the roof and by the fresh-air inlet. 

The siphoning of traps in houses of two and three 
stories, in which the fall of water is not so heavy and 
the momentum conseciuently not so great, can be 
prevented by the ''non-siphoning" traps. 

It is only in large houses, tenements, factories, etc., 
that the problem of si])honage demands the installa- 
tion of a new^ system of ])ij)es called ''vent-" or "back- 
air" ])ipes. These run vertically through the houses, 
and by their })ranches join all the traps near their 
crown and thus furnish a column of air for the water 
seal in the traps. This air prevents siphonage be- 
cause it is more easily withdrawn during the aspiration 
process than the heavier water in the traps. 

The vent-pipe system serves also as an additional 
means of ventilating the whole pipe system. The 
objection against the venting pipes is the additional 
expense. While most municipalities strictly demand 
vents in all houses, there is reason to believe that the 
practice of installing a special vent system will not 
last very long, especially in private dwellings. At 
present the tendency is toward simplification of the 
pipe system of the house. In the so-called '' one- 
pipe system" of plumbing the vent pipe is omitted, 
and siphonage is prevented by the installation of 
"non-siphoning" traps. 

PLUMBING PIPES AND FIXTURES. 

The plumbing system consists of the various fix- 
tures, such as sinks, wash-basins, laundry and bath 



PLUMBIXa PIPES AND FIXTURES ()7 

tubs, and the water closets. All these fixtures lead 
into the three main vertical pipes within the house, 
viz., waste and soil pipes, with the veid pipes accom- 
})anying them. All the vertical pipes in turn lead 
into the horizontally running main house drain which 
connects with the street sewer through the short house 
sewer. 

House Drain.^The house drain is the main pipe. 
It receives all the drainage from the vertical pipes in 
the house and carries it to the street sewer. 

The house drain is not level, but has a pitch or fall, 
in order to assist the velocity of the flow of its con- 
tents. The rate of fall should not be less than half 
an inch to the foot, although some municipalities 
allow a fall of a quarter of an inch to the foot. The 
rate of the fall depends also on the diameter of the pipe. 

The position of the drain under the house should 
be above the cellar; on the cellar floor, or under the 
ground. There is the greatest objection to the plac- 
ing of any plumbing pipe out of view; especially is the 
general practice of hiding the house drain under the 
cellar floor very bad, as it conceals the frequent 
defects of construction, joints, etc., and is likely to 
cause great damage to the cellar and foundations by 
saturating them with offensive effluvia before the 
defects are detected. When the house drain runs 
above the cellar it should l)e properly supported, 
either by brick piers or by suitable hangers to the 
wall. When it runs on the cellar floor the house 
drain should rest in specially constructed concrete or 
cement beds, and in trenches with proper beds for 
the hubs. 



68 HYGIENE OF HABITATIONS 

The house drain is separated from the house sewer 
by the main house trap, which is situated near the 
inside house wall. It should be provided with hand 
holes for cleansing ])urposes, and with tide valves 
when there is a ])()ssihility of back pressure by tide 
or storm. These hand holes should be closed by 
brass screw ferrules. 

The fresh-air inlet is a cast-iron pipe about four 
inches in diameter. It enters the house drain on the 
house side of the main trap, and extends to the outer 
air at or near the curb, where, as a rule, it terminates 
in a receptacle covered by an iron grating in the 
sidewalk. This form of fresh-air inlet is almost always 
ineffective, because the iron grating and the fresh-air 
box are commonly full of rubbish and dirt. The 
extension of the fresh-air inlet pipe several feet above 
the ground, properly protected by a wire basket or 
otherwise, and placed at a distance of at least fifteen 
feet from windows, is preferable to the ordinary 
fresh-air box. 

The Soil and Waste Pipes. — The soil pipes receive the 
sewage from the water closets and the bath tubs which 
are commonly located in the w-ater-closet apartments. 

The soil pipe is made of heavy cast iron, with lead-* 
calked joints, and is three or four inches in diameter 
in small houses and five inches in tenement houses 
and larger buildings. The soil and waste pipes should 
never be built in the walls, but should be exposed 
throughout their w^hole length, so that they can be 
inspected at all times and that defects may be seen 
as soon as they occur. If the pipes are gas-tight 
there is no reason to fear their exposure. With proper 



PLUMBING PIPES AND FIXTURES 69 

bronzing or painting they need not be artistically more 
objectionable than exposed steam pipes. Specially 
built shafts in which the pipes are sometimes placed 
must be made wide enough to allow entrance, inspec- 
tion, and repairs. 

The waste pipe is the pipe to which sinks, laundry 
tubs and basins are connected. It is" of heavy cast- 
iron with lead-calked joints, and varies in diameter 
from three to four inches. 

Waste and soil pipes should not end in the house, 
but should be extended open above the roof, at least 
two feet above every coping. As the extension must 
be at least four inches in diameter, two- and three- 
inch waste pipes will have to be increased to four 
inches in the extension pipe above the roof. Pipes 
of larger diameter should run above the roof. 

Branch soil and ivaste pipes run from the various 
fixtures to the main soil and waste pipes, join with 
''Y" branches, and are of lead when less than four 
inches in diameter and of iron when four inches and 
above. Branch waste pipes from basins, sinks, and 
tubs are usually one and a half inches and tw^o inches; 
branch soil pipes of water closets are three inches and 
four inches (in New York not less than four inches). 
The traps on the branch soil and waste pipes are not 
more than two feet from the fixture, and are provided 
with a screw cap for cleansing purposes. 

Vent pipes and branch vents are of iron. The size 
of main vent pipes depends upon the number of 
fixtures with which they are connected. The main 
vents either run above the roof or join the vertical 
pil)es above the fixtures. 



70 HYGIENE OF HABITATIONS 

Rain leaders serve to collect the rain water from 
the roof. They are made of galvanized or cast iron, 
or of sheet nietjd. The vertical i)ipe only is trapped 
at its hase before connection with the house drain. 
The ostensible purpose of this traj) is to ])revent sewer 
air from escaping into the rain leader and entering; the 
rooms near the windows of which the rain leader 
runs. As the traj) of the rain leader is frequently 
empty, owing to evaporation during draughts or 
freezing during winter, and as the rain leader is situ- 
ated outside of the house, there does not seem much 
reason for its being trapped. 

Fixtures. — Sinks, wash basins, laundry and bath 
tubs are made of various materials. From a sanitary 
point of view the worst material is wood, which was 
formerly much used; zinc or copper lining is not 
much better; somewhat better is cast iron. The more 
modern fixtures are invariably made of enamelled 
iron, which is smooth, durable, and sanitary in all 
respects. Porcelain fixtures are more expensive, but 
their advantage over enamelled iron w^hen properly 
made is small. 

Bath tubs are commonly in the same room with 
w^ater closets. They are connected wdth the soil pipes 
several feet below the water-closet connection, and 
if not vented the traps are apt to be siphoned by the 
discharge of the w^ater closets. 

The overflows from bath tubs and basins should be 
connected on the inside of the trap on the same fixture. 
Standpipe overflows are preferable to fixed ones. 

Refrigerators should not be directly connected w ith 
the plumbing system of a house, but their w^aste pipes 



WATER CLOSETS 71 

should be made to discharge into properly trapped, 
sewer-connected, water-supplied open sinks. 

The sediment pipes of kitchen boilers should be 
connected with sink traps on the inlet side, and should 
be provided with faucets. It is still better not to 
connect them with the pipes. 

All fixtures should be separately trapped, except 
that one trap is permitted for (several not more than 
three) laundry tubs, and one line. 

WATER CLOSETS. 

Water-supplied fixtures of some sort or other for the 
receiving of fecal matter have been in use for many 
years, l^nfortunately the type of the fixtures which 
have been extensively used until lately embodied many 
defects which made them unsanitary. Of the older 
fixtures it is sufficient to name the so-called " pan water 
closet," the ''plunge closet," the "school sink," the 
" long hoppers," the "wash-out closet," etc. 

Modern Water Closets. — These are made of baked 
clay or porcelain, with an enamelled and smooth sur- 
face, trapped and bolted in one piece, and so arranged 
that the excreta drops into the receptacle, always 
containing water, from which the soil is properly 
flushed out and the whole cleaned out every time it 
is used. The value of these fixtures depends not only 
upon their shai)e, but also upon the methods of their 
flush and the abundant supply of water. Formerly 
the water closets were flushed directly by a pipe 
connected with the fixtures. This, however, was found 
to be defective by reason of the insuflficiency of the 



72 ' HYGIENE OF HABITATIONS 

volume of water furnished. The method used at 
present is the flushing of these fixtures by means of a 
separate flush tank placed at least four to six inches 
above the fixture. These tanks hold from three to five 
gallons of water, are connected with fixtures by flush 
pipes of one and a half inch in diameter, and are 
emptied by the pull of a chain. In some ])ublic i)laces 
these tanks are so arranged that they automatically 
discharge their contents at certain intervals. The 
added cost of the flush tanks has caused various 
devices to be invented, with the view of eliminating 
their installation. There are a number of efficient 
" flushometers" which are used for this purpose. 

Water-closet Apartments. — The undesirability of plac- 
ing the water closets in the yard has already been 
mentioned. It is unnecessary to add that the water 
closets should never be placed in cellars. There are 
also grave objections against water closets in halls, 
which are frequently found in tenement houses. In 
office or public buildings there is perhaps no reason 
w^hy the water-closet apartments should not be located 
in a separate compartment in the hallways, but in 
tenement houses this is objectionable on account of 
the neglect of the fixture if responsibility is divided 
and each tenant has not his own separate fixture. 

Wherever the fixture is placed, there are several 
requirements which ought to be absolutely adhered 
to; these are the following: Sufficient space, plenty 
of natural light by adequate window space opening 
into the outer air, provision for artificial light, pro- 
vision for beating in cold weather, smooth and non- 
absorbent walls and ceilings, a floor of cement, con- 



HOUSE WASTE MATTERS /3 

Crete, slate, tile, or any other non-absorbent and 
readily cleansible material. If in addition there is 
separate entrance from the private hallway, and the 
apartments are placed at some distance from bed 
rooms and living rooms, the least objectionable, most 
advantageous location and construction of these 
necessary, though sometimes offensive, conveniences 
is obtained. 

HOUSE WASTE MATTERS. 

Waste Matter: Rubbish and Garbage. — A large amount 
of various waste matter is found in the house, such 
as newspapers, rags, wool, and cloth remnants, pieces 
of clothing, rags, detritus of wood, stone, and other 
articles; also remnants of foodstuffs, cooked and 
uncooked meats and vegetables, etc. 

Some rubbish may be harmless, but it may become 
a vehicle and carrier of dust, dirt, and possibly patho- 
genic germs. Remnants of cloth and rags may be 
saturated with organic matter, or contain insects 
and parasites, as well as ill-smelling and foul organic 
material. 

Garbage, consisting of remnants of foodstuffs, is 
apt to putrefy and decompose, to attract insects and 
rats, to emit foul odors, or it may contain dangerous 
microorganisms. 

Waste Water and Sewage. — This consists of the water 
used in washing dishes, clothes, vegetable and animal 
food, and in cleaning; of waste water from baths, 
etc., and also of liquid and solid excreta. 

In houses provided with modern water-carriage 
])lumbing systems most of the waste water and sewage 



74 HYGIENE OF HABITATIONS 

is effectually disposed of by beiiij:: carried away into 
the house and the street sewer and flushed by copious 
discharges of water. Whenever houses are without 
a system of plumbing, accumulation of the waste 
matter may become dangerous to health on account 
of decomposition and foul odors and the ])resence of 
micnxirganisms. 

Gases and Poisons. — The character of the various 
gases and poisons which may be found in houses 
vary, bnt the most conunOn are the following: Car- 
bon dioxide, coal gas, carbon monoxide, illuminating 
gas, smoke, ''sewer gas," and of the poisons the most 
common are arsenic, lead, antimony, etc. 

Carbon Dioxide. — Carbon dioxide is a constituent of 
the air in the proportion of .3 or 4 volumes in 1(),()0() 
volumes, but in some ill-ventilated rooms the amount 
of carbon dioxide may reach from 20 to 50 times the 
normal amount. There is comparatively little danger 
to health from carbon dioxide unless it is present in 
excessive quantities. 

Carbon Monoxide. — Carbon monoxide is a constit- 
uent of illuminating gas and comes into the house 
from various defects in the gas pipes and fixtures 
through which the gas may escape. The inhalation 
of even minute quantities of illuminating gas is in- 
jurious, and may cause headache, anemia, etc. The 
inhalation of large quantities may cause death by 
suffocation, a^ the carbon monoxide combines with 
the hemoglobin of the blood. The escape of illumi- 
nating gas is also a frequent cause of fires and explo- 
sions which endanger property and life. Carbon 
monoxide is also given off by imperfectly burning 



HOUSE WASTE MATTERS 75 

illuminants, by charcoal huruing, and by imperfect 
heating arrangements and imperfect combustion of 
coal, as well as by iron stoves which are allowed 
to become red hot. 

Smoke and Coal Gas. — Imperfect combustion of 
wood and coal produces smoke and coal gas. Their 
presence is also due to faulty chimneys, back draught 
from fines, partial closing of dampers, etc. Smoke 
causes inflammations of the conjunctiva, headaches, 
nausea, ill-feeling, vomiting, and in large quantities, 
suffocation. 

Sewer Gas. — As already indicated, what is com- 
monly called "sewer gas" is only the air in sewers 
and plumbing drains and pipes. It may be entirely 
free from any deleterious matter, but frequently con- 
tains various gases, such as ammonia compounds, 
marsh gas, sulphuretted hydrogen, etc., which arise 
from the decomposing organic matter within the 
pipes. The effluvia escape through defects in the 
plumbing system, and their harmfulness depends 
upon their quantity and character. 

Poisons. — Wall paper colored with poisonous dyes 
is the most common source of the various poisons 
which may be found in the air of rooms. Minute 
])articles of the wall paper floating in the air, the 
rubbed-off coloring matter adhering to dust, and 
scraped-off debris from painted surfaces may all 
contain arsenic, antimony, lead, and other poisons. 
Numerous cases of arsenical poisoning by wall paper 
have been reported, and in some countries, notably 
France and (iermany, the use of arsenic for coloring 
wall paper is prohibited by law. Lately, Nephe tried 



76 HYGIENE OF HABITATIONS 

to prove that poisoning by arsenical paper is not due 
to the dry dust, but to the volatile organic arsenical 
compound produced in the moisture present by the 
action of certain moulds on the paste used to attach 
the paper. Most American manufacturers of wall 
paper claim tliat no arsenic or other jmisons are used 
at present in the manufacture of wall papers. 

The presence of lead may be due to the dust from 
lead-painted walls and surfaces. 

Dust and Dirt. — Dirt and dust may be organic or 
inorganic, coarse or fine, and generally consist of 
fragments and particles of earth, soil, clay, stone, 
brick, wood, lime, plaster, hair, wool, animal and 
vegetable matter, ashes, pulverized excreta of animals 
and insects, dried sputum and discharges of the healthy 
and sick, pollen of flowers, pulverized wool, cotton 
and silk fabrics and clothes, moulds, fungi, and sapro- 
phytic and pathogenic germs. 

The street and the outside of the house contribute 
a large part of the house dirt and dust. Some of it 
gains access through open windows and doors or other 
openings, but most of it is brought in by the dw^ellers 
on their clothes, skirts and shoes. 

It is, of course, useless to preach against the com- 
mon habit of not discarding in the house the shoes 
w^orn in the streets and fields. These shoes carry 
manure, organic refuse, moist and dried excreta of 
man and animals, moist and dry discharges from the 
sick and well, sputum of consumptives, and millions 
of germs. Why such receptacles, laden with germs of 
disease, should not be left behind when coming into our 
" sweet homes," as is done by the " benighted" Orientals, 
is a question the answer to which is vainly sought. 



HOUSE WASTE MATTERS 77 

It is also useless to decry the equally unhygienic 
habit of women of wearing trailing skirts which drag 
along and sweep up the pavements of the streets and 
sidewalks as well as the gutters, gathering the rich 
harvest of the same dangerous matter and bringing 
it into the house. 

The house itself is a source of dirt and dust. Frag- 
ments of walls, floors, and ceilings, various objects 
like furniture, plants, flowers, also the various pro- 
cesses carried on within the house, such as sewing, 
cooking, lighting, heating, etc., all furnish their quota 
of the dirt falling upon the various surfaces of the 
house, and of the dust floating around in the air and 
settling upon various objects. 

The most important source of dirt and dust is, of 
course, man himself. Dirt and dust are brought in by 
persons upon their clothes and bodies. Considerable 
filth is due to the discharges from animals and human 
beings, and a very large part of the house dirt is due 
to the filthy habit of expectoration. 

In his booklet on Dust and its Bangers, Dr. 
Prudden expresses himself in the following forcible 
manner about expectoration: "The spectacle of the 
well-dressed, filthy brutes, whom natural selection 
has most unkindly left but a few degrees higher than 
their congeners in the sty, wallowing in their expec- 
toration, about certain hotels and theatre entrances, 
may well impress the sensitive onlookers with the 
colossal task which nature undertook when she set 
to work to evolve man, and the lamentable failures 
which are so often but half-concealed in fashionable 
attire," 



78 HYGIENE OF HABITATIONS 

The Dangers of House Dust. — The character, the 
quantity, the sources of the dirt and dust as well as 
the individual susceptibility and healthy condition 
of the house dweller are all determining: factors in 
the amount and intensity of the danger to health and 
life. 

The inhalation of dust is injurious to the mucous 
membrane of the nose and throat, and may cause 
inflammation and catarrh of the respiratory tract. 
Dust consisting of the scales from the skin of })ersons 
suffering from measles and scarlet fever is apt to 
produce the same disease in healthy persons coming 
in contact with it. 

The greatest danger from dust comes from the 
pathogenic germs which adhere to it. They come 
from the dried sputum, skin scales, and other dis- 
charges of infected persons which contain the specific 
microbes of various specific diseases. The dust con- 
taining tubercle bacilli from the sputa of consump- 
tives, the dust containing the germs of typhoid fever 
from discharges of typhoid patients, and the other 
microorganisms from the many infectious and con- 
tagious diseases are, of course, very dangerous and 
capable of producing those diseases in healthy persons 
either by inhalation, or by ingestion through food. 
That such infectious germs are abundantly found 
within the house has been proved by the experiments 
and investigations of many hygienists. 

In many houses, especially those which are damp, 
there are found a number of low moulds, mites, and 
fungi, some of which are dangerous to health. Among 
the most important of these is the fungus of "dry 



HOUSE WASTE MATTERS 79 

rot," " Hausschwamm, or Merilius Lacrymans," which 
is found ill damp houses. 

llie organic matter which is abundantly found in the 
dirt and in the superimposed layers of dust upon all 
surfaces within the room is dangerous to health 
because of the putrefaction and decomposition going 
on within it, because of the foul and disgusting odors 
emanating from it, and also because of the various 
pathogenic germs which may be found in it. 

\Yhen horse manure is a part of the organic dirt 
of the house it may contain tetanus bacilli, which 
may lead to infection with that dread disease. Also 
abundant organic matter, especially in dark and 
damp places, attracts rats and insects. 

Domestic and Other Animals. — Domestic animals 
are often a source of danger. The common pets are 
dogs, cats, birds, and more rarely, rabbits, squirrels, 
monkeys, etc. The sources of danger to health from 
the animals are (1) in their excreta, (2) from the para- 
sites living upon them, (3) from the dirt and germs 
which they may carry in upon themselves from out- 
side, and (4) from the diseases Avith which the animals 
themselves may be afflicted. 

Among the diseases of domestic animals which may 
be transmitted to man are ringworm, favus, scabies, 
tetanus, anthrax, glanders, actinomycosis, "psitta- 
cosis" (a pulmonary disease of parrots), influenza, 
diphtheria, plague, etc. 

Rats are not exactly domestic animals, but they 
may infest houses and become a veritable pest. Their 
presence is favored by the construction of the house, 
which leaves a hollow space between the walls and 



80 HYGIENE OF HABITATIONS 

floors and by the food and drink which tempt these 
voracious animals. Rats have been proved to be, 
very dangerous as carriers and transmitters of plague, 
and ])r()bably other diseases. Their excreta de})osited 
in foodstufl's may cause intestinal infection in man. 
Fleas and otlicr parasites of rats may be carried 
to the human inhabitants and may infect human 
beings with ])lague and other diseases with which 
the rats may be afflicted. 

Insects. Houses harbor a number of uninvited 
guests, who not ()nl> make the lives of their host 
miserable, but may even become a source of grave 
danger. Besides rats and mice, the most disagreeable 
of the uninvited guests and pests are the various 
insects with which some or most of the houses are 
teeming. These insects are the following: Roaches, 
water-bugs, beetles, centipedes, spiders, lice, fleas, 
bed-bugs, and last but not least, the mosquito. 

The very presence of these insects is disagreeable, 
either on account of their repulsive looks, or of their 
odors, or because of their bites. Moreover, the mode 
of feeding of most of these insects is objectionable 
to the human dwellers, who themselves are the hosts 
that furnish the sustenance. 

Relation of Insects to Disease. — Many of the 
insects in the house may become agents in the trans- 
mission and carrying of disease. The mode of propa- 
gation of disease by insects is by (1) transmission, 
(2) direct inoculation through their bites, and (3) by 
becoming the intermediate hostsof some infectious germs. 
Transmission. — ^There is little doubt that insects 
can transmit disease germs by means of their bodies. 



HOUSE CLEAMXG 81 

leg:s, wings, etc., which may come in contact with the 
food, clothes, and skins of himian beings. Thus, 
they disseminate disease directly from one person to 
another. Flies, on account of their prevalence and 
their habit of coming in contact with excrementitious 
materials outside of the house and with the food and 
drink inside of the house, are the most active agent 
in disease dissemination. 

Inoculaiion. — That certain insects by their bites 
inoculate human beings with the germs of diseases 
from which they themselves suffer lias been siu-mised 
by many scientists for a long time, but definite proof 
of tliis has only lately been obtained in the matter of 
the transmission of plague in which the role of fleas, 
bugs, and rats is prominent. 

Intermediate Hosts. — Some insects become the 
intermediate hosts of certain specific and dreaded 
infectious parasites, which must pass through an 
intermediate stage in insects before they develop into 
full-grown parasites capable of infecting human 
beings. The mosquito, which has been proved to 
be the cause of malaria and yellow fever, diseases 
wliich count their victims by hundreds of thousands, 
is a notable example. 

HOUSE CLEANING. 

The presence in the house of so many and such 
varied impurities so dangerous to health and life, 
makes the problem of their prevention, their removal, 
and their destruction an important task. 

The war waged by the house dweller against all 
6 



82 HYGIENE OF HABITATIONS 

kinds of iin])urities must be remorseless, constant, 
thorough, and exhaustive, for if hut a short armistice 
is granted the enemies of mankind arc likely to ^et 
the upper hand and increase to an extent which makes 
their final dislod<:;mcnt most difficult if not impos- 
sible. The methods of wjirfare against house impuri- 
ties are threefold, aiming at (1) the i)rcvcntion of 
the admission of hlth, organic matter, etc.; (2) clean- 
ing and rcmo\ing impurities from the house; {'^) the 
destruction of infectious materials. 

Prevention. — To prevent the accumulation of waste 
matter, })aper, rubbish, etc., such stuff's should im- 
mediately be collected in closed receptacles and 
cremated. This may be done in ordinary stoves, 
ranges, and furnaces, or in special furnaces for the 
purpose, which should be more extensively intro- 
duced. It will surprise some housewives to learn how 
easily they may get rid of most of the house w^aste, 
as well as the garbage, in a well-constructed furnace, 
and how^ much this assists in keeping the house clean. 

Waste water and sewage are disposed into the 
plumbing system with which each house should be 
provided. In rural communities, in which no sew^er 
system is provided, the sewage and house- waste 
water may also be sent into a house-plumbing system, 
which empties into cesspools, or, better, into land 
irrigation. When no system of house plumbing 
exists, all waste water may be sent through rubber 
pipes into the kitchen garden, and the solid sewage 
may be collected in earth closets and used later as 
fertilizer. 

The removal of the sources of danger coining 



HOUSE CLEANING 83 

from various deleterious gases and poisons consists 
in the proper construction of the house, its sanitary 
conveniences, and its proper maintenance, (iround 
air from the cellar may be prevented by a thorough 
isolation of the house foundation from the soil by 
means of damp-proofing materials, and also by a 
proper ventilation of the cellar. Leaks from illumi- 
nating gas pipes and fixtures may be prevented by 
a proper and good construction of the pipes and 
fixtures, and by periodical inspection and care, also 
by periodical and frequent tests of the whole system. 

This also applies to the plumbing pipes and plumb- 
ing fixtures. The pipes and fixtures must be properly 
constructed, all joints made gas-tight, the whole 
system frequently inspected, and periodical tests 
made to detect defects and leaks. Hand holes of 
traps and screw caps of traps should be uncovered 
and the traps cleaned out, and all sink and wash- 
basin traps and pipes cleaned once in a while by 
solutions of caustic soda or potash. 

Smoke and coal gas may be kept from entering 
houses by a proper construction of the heating and 
cooking stoves and furnaces, by the skill in feeding 
them with proper fuel, by the care of chimneys, flues, 
and dampers. 

The best prophylaxis against arsenic and lead and 
other poisons in the house is the disuse of papers and 
paints containing those poisons as ingredients and 
the substitution of papers and paints free from toxic 
elements. There is really no justification for the use 
of any materials of which some ingredients may become 
dangerous to the house dwellers. 



84 HYGIENE OF HABITATIONS 

The i)revcntion of dirt and dust within the house 
is one of the most important sanitary measures. 
With proper care in construction and maintenance 
there is no reason why it should not be possible to 
make houses dustless and dirtless. 

With the installation of an ideal system of me- 
chanical ventilation it is j)()ssible to eliminate all the 
dust coming into the house through windows and 
openings. These may then remain closed, and all 
incoming air may be filtered and passed through 
appro])riate materials which will intercept all dust and 
leave the incoming air pure and dustless. 

Until the question of discarding the shoes worn 
outside before entering into a house, and the even 
more difficult one of women's skirts is settled, some 
substitute prophylactic measures must be provided, 
such as special vestibules in houses, with some me- 
chanical means of cleaning shoes and brushing off 
skirts. There is no inherent difficulty in the construc- 
tion of such mechanical cleaners, and their installation 
would do infinite good and prevent much harm. 

Other means of preventing dirt and dust are the 
proper hygienic construction of house interiors, and 
the elimination of certain dust- and dirt-gathering 
objects wdthin the house. The elimination from the 
house in all dust-gathering objects is absolutely 
necessary. Thus carpets, rugs, curtains, soft stuffs, 
upholstered furniture, w^all paper, and all other dust- 
gathering and retaining materials and objects must 
be removed and kept out if the house is to be 
rendered dustless. 

Moulds, germs, mites, fungi, and bacteria will also 



HOUSE CLEANING 85 

disappear from the house if these preventive meas- 
ures against dust and dirt are universally adopted. 
The additional precaution of keeping the house dry 
and well-aired will further diminish the presence of 
these impurities by removing the conditions of life 
favorable to their growth and development. 

The keeping of domestic animals within the house 
is incompatible with hygienic housekeeping. The 
ordinary precautions of bathing and washing them 
and of consulting veterinarians in case of sickness 
may diminish the dangers, but will not entirely 
eliminate them. 

The prevention of the rat and mice pest is a more 
difficult problem, for these animals do not wait for 
an invitation to enter houses. The solid construction 
of walls and floors, the proper construction, lighting 
and ventilation of cellars and pantries, the imme- 
diate cremation of all garbage and organic matter used 
by them as food, the absolute cleanliness of kitchens, 
the keeping of food in tight receptacles, the use of 
rat traps, and periodical inspection and cleaning of 
the house are some of the methods of preventing the 
living of rats and mice in the house. If these meas- 
ures fail, war-like methods, like poisoning and periodic 
fumigation with sulphur, must be adopted. 

The prevention and eradication of house insects is 
no less difficult. Beetles, water-bugs, cockroaches 
spiders, and similar insects may be eliminated from 
the house by the following means: By measures 
against house dampness and the maintenance of the 
dryness of the kitchen floors, walls, and cellars; the 
construction of floors and walls without cracks and 



86 HYGIENE OF HABITATIONS 

crevices, the absence of any hidiii^^ and dark ])laces 
for the hal)itat of insects; the fre(|nent insptH'tion. 
periodic and thorouj^h cleaning of all rooms, and, 
especially of those in which the j)resence of the insects 
is noticed; the dusting of snrfaces where some of 
these insects live with horax, horacic acid, or some 
other antiseptic and germicide; and finally, as in the 
case of rats and mice, ])eriodic fnmigation. 

Fleas and lice can be eliminated by the removal of 
domestic animals, by removing carpets and similar 
objects, and by the absolnte cleanliness, in body and 
clothes, of the inhabitants. 

The elimination of the noxions bed-bng is difficult. 
It needs eternal vigilance on the part of the house- 
keeper; it needs absence of cracks in walls and floors, 
the more extensive use of light, airy, single, metal bed- 
steads and light, easily handled mattresses; it needs 
periodic inspection, thorough cleaning, and occasional 
fumigation. 

The elimination of the fly demands proper screen- 
ing of windows and doors; covering of all foodstuff 
with wire-mesh covers; the keeping of kitchens and 
dining-rooms in a proper and clean condition, free 
from scraps of food, garbage, and organic matter; 
and constant warfare by cleaning, disinfection, fumiga- 
tion, etc. 

The ravages of the mosquito must be prevented 
by draining all marshes and standing water near 
human habitations and towns, and the destruction of 
their larva by the use of kerosene oil. 

Means and Methods of Cleaning. — The common 
methods of house cleaning are WTong in principle, 



//O^^S'E CLEANING 87 

faulty in tluMr execution, and futile in their efforts. 
The common (hy method of cleaning by the house- 
wife and servant is by means of the broom, brush, 
duster, and feathers. These instruments, instead of 
cleaning the house, raise the dust, flap around the 
dirt, disturb quietly lying matter, and disseminate 
infectious material otherwise harmlessly resting in 
peace. 

It is remarkable that centuries of progress have not 
helped to evolve a more rational and sanitary method 
of housecleaning. The common wet method of clean- 
ing is not much more efficacious. The scrubbing of 
floors, spilling of pails of water upon floors and sur- 
faces, soaking the woodwork, rendering it damp and 
mouldy, are not ideal methods of cleaning, likely to 
assist in the elimination of dirt and house insects. The 
carpet sweeper and dry-rag duster may be included 
among abominations in house cleaning. 

Undoubtedly the best method of cleaning is by 
means of the vacuum cleaners. Some of these are 
portable and operated by hand power or by electricity; 
others are installed in the house as a whole system 
with tubes and piping to all rooms, and special ar- 
rangements which make the exhaustion of dirt and 
dust a matter of little difficulty. No greater evi- 
dence of the enormous amount of dirt found in the 
carpets and rooms of houses is needed than the barrels 
and barrels of dirt which these vacuum cleaners collect. 
The onl>' objection against them is their expense, but 
with their luiiversal introduction this may become 
smaller. 

The other rational method of cleaning is by going 



88 HYGIENE OF HABITATIONS 

over all the walls of rooms and the objects in the 
rooms with damp ra*i;s, thus remo\inu; the dust and 
dirt; occasionally some mild antiseptic, such as tur- 
pentine, carbolic acid, or a weak solution of corrosive 
sublimate, should })e used. 

In house cleaning it is of the utmost im])ortance to 
make the ])rocess thorou*;h, reticular, and j)eriodic. 
Houses and rooms must be cleaned daily, weekly, 
monthly, and a special cleaning nnist be given every 
three months at the end of the season. 



CHAPTER III. 

THE HYGIENE OF FOODS AND FOOD 
SUPPLY. 

FOODS. 

"Food is that ivhich, when taken into the body, hnilds 
tissue or yields energy.'' Everything is therefore food 
which may be used for the purpose of replacing the 
wear and tear of the cells of the body, or of supplying 
heat and energy to the body, or of storing up such 
energy for future use. 

The following, while not strictly foods are also 
included: (1) certain materials, consisting of cellulose 
or wood fiber, which, though not serving to "build 
tissue or yield energy" are needed to give bulk to the 
foods ingested and serve a certain purpose in the physi- 
cal process of digestion; (2) water; (3) certain ingre- 
dients, called vitamins, the functions of which are not 
yet determined but the necessity of which are clearly 
manifested. 

Sources of Food. — The sources of human food are the 
animal, vegetable and mineral kingdoms. The flesh 
of a large number of domestic and wild animals is used 
as human food when specially prepared and modified. 
As food are also used a number of cereals, roots, vege- 
tables, fruits and nuts, either in the natural state or 
specially prepared and modified by art and science. 



00 HYGIENE OF FOODS AND FOOD SUPPLY 

We also use as food certain minerals found either in the 
natural state or as ingredients of other food products. 

(linuicdl ('(nupos'ifion. — In their fin;d analysis, all 
foods contain the elements: Carbon, hy(lr()<i;en, oxygen, 
nitrogen, sulphur, sodium, potassium, calcium, mag- 
nesia, etc. 

Most of the foods are derived from the organic 
world. The inorganic foods are the mineral matter and 
water. The organic foods are divided into two main 
groups: Nitrogenous and non-nitrogenous. 

T-T-. . • / Wliite of egfj;s, curd or casein of milk. 

Nitrogenous protein | ^^^^ ^^^^^^ ^j^^^^ ^^ ^^^^^^ ^^^ 

T-T -x X • / Carbohydrates: sugar, starch, etc. 

Non-nitrogenous protein ^ j,^^^. ^^.^^^^ vegetable. 

The RcJdiive Use and ]\t1ue of Each Food Compoveiif. 
—Each of the food components is essential to life. A 
certain amount, therefore, of each must be used in order 
to sustain and continue life. 

Protein. — The muscles, the blood, the lymph, and 
other parts of the human body and organs contain 
a large percentage of protein or albumin matter. 
There is a constant loss of these protein cells in the 
body metabolism, and consequently a need to repair 
and replace this loss. This is accomplished by the 
ingestion of foods which have a certain percentage 
of protein in their composition. All animal foods 
contain a large proportion of proteins, while vegetables, 
with a few exceptions, contain but a small proportion 
of protein. 

The chemical composition of protein matter depends 
upon its source. Thus there are different varieties 



FOODS 91 

of ])r()telii matter, siicli as the albumins, globulins, 
albuminoids, nucleo-albumins, peptones, etc. 

Carbohydrates and 7v//,s\— -The heat and energy 
of the body use up certain elements, such as oxygen, 
carbon, and hydrogen, and these must be replaced 
by food. The carbohydrates and fats supply this 
need. Fats and carbohydrates are to some extent 
interchangeable. The principal elements of food 
which furnish the carbohydrates are the sugars and 
the starches, which digestive processes convert into 
sugars. The fats are found in foods in the form of fat 
and oil. 

Mineral Matter. — The body contains a quantity of 
mineral matter which is found in the form of ashes 
when the body is burned. The minerals which have 
been enumerated are found in the body and are also 
needed as food for the formation of bone and as an 
aid to digestive processes. It is claimed that the lack 
of certain inorganic matters, especially acids, is capable 
of producing the disease called "scurvy" which is 
found among sailors and others who are deprived of 
foods containing those acids. 

Water. — The human body consists of two-thirds 
of its weight of water. The body loses water con- 
stantly through the lungs, skin, and excretory ducts. 
The amount of the daily loss of water depends upon 
many factors, and is estimated at from 2000 to 3000 
grams. There is therefore needed a considerable 
amount of water for daily use, and this is ])artly 
furnished by the water which is a component of nearly 
every food, and partly by the water consumed with, 
or in addition to, the food. 



92 HYGIENE OF FOODS AND FOOD SUPPLY 

Vitamiijs. — Under this term are grou])ed certain 
elements of food, the exact chemical composition of 
which is as yet unknown, hut the ])rcscncc of which 
ingrecHents is ahsohitely necik'd in foods to preserve 
the health and life of man. The absence of vitamins 
is known to have caused certain diseases, such as 
beriberi, scur\ \ . and ])()ssil)ly pella*]:ra, as well as other 
ill-defined conditions of health. I'hese \itamins are 
important to the well-beintj: of the body. They are 
foiuid in the skin and coatin*!; of ^jjrains, in the yolk of 
eggs, in raw meat, in fresh fruits, vegetables, etc. 

Celhlosr. — Cellulose is a constituent of vegetables, 
fruits, grains, etc. It is contained in a large measure 
in certain vegetables, like lettuce, celery, spinach, 
asparagus, cabbage, tomatoes, berries, etc. While 
cellulose is not strictly a food, it is necessary to give 
bulk to the foods ingested and to aid in the intestinal 
peristalsis. 

Estimates of Food Values. — Foods are necessary for 
the metabolism of the body. Like all organic sub- 
stances, foods, when oxidized, burned or metabolized 
in the body, produce heat. The exact amount of heat 
produced by a certain food, or a given quantity of a 
certain food, will differ according to the nature of the 
food and also according to the amount of water and 
elements incapable of producing heat which it may 
contain. 

Foods when ingested, digested and assimilated, 
produce the same amount of heat and energy as when 
burned outside of the body. Hence this amount of 
heat may be measured, standardized and serve as the 
criterion of heat and food values. The definite meas- 



FOODS 93 

lire of the heat \i\\\w of a food is the caloric. A calorie 
is the amount of heat required to raise one kilogram of 
water one degree Centigrade, or the amount of heat 
required to raise one pound of water four degrees 
Falirenheit. 

According to Rubner, one gram of protein or carbo- 
hydrate gives 4.5 calories while one gram of fat gives 
9.3 calories. 

According to Langworthy, one pound of protein or 
carbohydrate gives 1860 calories, while one pound of 
fat will give 4220 calories. 

We have therefore in these standards a means for 
finding out the caloric value of foods, provided we know 
what percentage of protein, fat and carbohydrate 
they contain. 

Dietetics and Preparation of Food. — By diet is under- 
stood the quantity, quality, and kind of food taken in 
by the person daily. 

There are a great many factors determining the 
value of the average person's diet. The main factors 
are as follows: 

The person: Age, weight, physical condition, race, 
condition of rest. 

The food: Chemical composition, physical condi- 
tions as to form, volume, consistency, percentage of 
edible and inedible parts, temperature, etc. 

General conditions: Climate, temperature. 

It is difficult to make hard-and-fast rules for dietetic 
standards. Human beings adjust themselves easily 
to different kinds and forms of food, and during 
health, as a rule, do not sufl'er much except when they 
take either^too nuich or too little food, or are fed ex- 



94 HYGIENE OF FOODS AXD FOOD SUPPLY 

clusively on one food or on food which lacks some of 
the necessary nntrient in<iredients. 

A })rol()n<i:ed and constant overuse or underuse of 
certain food element is hound to cause })athological 
conditions and is the cause of certain diseases of 
digestion and metaholism. 

The form and consistency of food is of much impor- 
tance, for food must he in such condition as to be 
readily di^rested. Many foods nnist he mechanically 
ground hy the teeth; some are chemically acted 
uj)on in the mouth by the processes of mastication. 
This not only ])re])ares the food for the stomach by 
softening and dividing it into small particles, but also 
aids much in the conversion of starches of vegetables 
and cereals into sugars. 

There is still much controversy as to the value of 
an exclusively vegetarian diet, as well as to the com- 
parative percentage of the protein and carbohydrate 
elements needed for persons. For the average healthy 
person a mixed diet of animal and vegetable food is 
probably the most appropriate, and the amount of 
the protein matter must be somewhat limited, much 
depending upon the physical condition and habits of 
the person. 

The cost of food depends also upon very many 
factors. Often it is not the most costly food that is 
the most useful or nourishing, as some of the causes 
of the high cost of food are its rarity, difficulty of 
obtaining it, the manner of preparation, the place 
where it is sold, and the matter of taste. For physical 
subsistence, cereals, vegetables, nuts, fish, and flesh 
of animals furnish all the necessary nutrient qualities, 



FOODS 95 

and some among these are of comparatively low cost, 
their nutritive value being, however, quite as great, if 
not greater, than that of the more costly foods. 

Rau\ Cooked, and Prepared Foods. — Some cereals, 
a large number of vegetables, most of the fruits, a 
number of nuts, and some forms of animal foods may 
be taken in their natural state. The flesh of animals 
is seldom used raw, although the fat is often so used 
and in some climates the flesh is also eaten raw. 

The process of cooking foods greatly improves the 
consistency and form of most foods, develops the 
flavors, increases the digestibility, improves the taste, 
and generally enhances the value of food for human 
beings. Much of the increased digestibility and value 
of the food depends upon the various forms and pro- 
cesses of cooking. 

The food may be heated (pasteurized at 160° F. 
for ten minutes). This process destroys certain patho- 
genic germs, softens the food, and is valuable for the 
preparation of milk, for the cooking of soft-boiled 
eggs, etc. 

Boiling, stewing, steaming, baking, roasting, and 
frying are some of the various modes of subjecting 
foods to heat. The value of each process depends 
more or less upon the kind of food and various other 
conditions. 

In stewitig, the food , is cut into small pieces and put 
in cold water and heated slowly. This is an economic 
method of preparing certain meats and vegetables. 

Boiling is a more rapid process in which the food is 
put into hot water and kept at a boiling temperature. 

Certain foods, especially fruits and cereals, are more 



96 HYGIENE OF FOODS AXD FOOD SUPPLY 

tender and digestible when })repare(l by means of 
steaming. The food is plaeed in a (h)uble pot, the 
water is boiled in the lower ])art, and the food in the 
upper part is subjected to the steam formed by the 
heat. 

Udkhuj and nxisiiiu/ are processes by which the 
food is exposed to the dircu't radiation of heat in open 
or enclosed ovens. 

Frying is a form of roasting in which the food is 
placed ill a j)aii and fried in fat. 

l^oiling and frying somewhat toughen the fibers of 
the food and render it less digestible than the other 
processes. 

Care, Storage, and Preservation of Food. — All foods 
when left exposed for some time undergo a process 
of deterioration and decomposition. This is due to 
the breaking up of organic tissue into its simple com- 
ponents, and finally into its primary elements, the 
decomposition being due to the action of microorgan- 
isms. The majority of the microorganisms which 
cause the breaking up of the tissue of the foodstuffs 
are harmless. The deterioration of food is also due 
to various moulds, yeasts, and other vegetable and 
animal germs which are found almost everywhere. 
In order to prevent the deterioration of foodstuffs, 
the action of the destroying germs must be inhibited 
or stopped. 

Foods that are overripe or underripe, that have 
fungi, parasites, or w^orms in them, or that lack pro- 
tective coverings, usually undergo more rapid decom- 
position. Certain foods, when in a process of decom- 
position develop chemical poisons which cause serious 



FOODS 97 

disturbances in those eating the foods. These are 
sometimes called ptomain poisoning. 

In order to care, store, and preserve foods in the 
house, certain conditions are necessary: (1) A sound 
condition of the food; (2) dry air; moisture is abso- 
lutely necessary to decomposition, and its presence 
favors the growth and development of low organic 
and bacterial life; absence of moisture is a preven- 
tive against decomposition; (3) absence of flies and 
insects: certain insects injure the food and also bring 
to it germs which aid in decomposition; all foods 
must be examined and covered to prevent the access 
of these insects. It is best to have all foods covered 
or wrapped in protective coverings so as to prevent 
their injury from the outside agents. 

Temperature. — A low temperature, even below the 
freezing-point, does not kill bacteria, but it stops and 
inhibits their further growth. iVt a temperature of 
40° to 45° F. the growth of germs is greatly retarded, 
and this is the best temperature at which to keep and 
store foods. 

Food in houses is stored in separate rooms, pan- 
tries, cellars, or ice-chests. Wherever it is stored 
care must be taken to have an equable temperature, 
below 45° F., and as far as possible each food should 
be separated and ke])t apart from other foods. 

Drying. — The method of drying foods in order to 
preserve them is efficient in proportion to the thor- 
oughness of the process. Drying is ada])table to meats, 
cereals, seeds, and some fruits. The drying is done 
either in the sun or on fires. Some foodstuffs may be 
preserved for a long time. 
7 



98 HYGIENE OF FOODS AND FOOD SUPPLY 

Salting and Pickling. — Salting and pickling are 
partly chemical and partly physical methods of food 
preservation. Salt prevents decomposition by reason 
of its antiseptic qualities and by its absorption of 
moisture. This method is api)licable to meats and 
fish. Fish are also preserved in brine or salt solution. 
Pickling is the keeping of food, such as fish, certain 
vegetables, and fruits, in vinegar. These ])rocesses 
harden to some extent the fibers and diminish the 
digestive (}ualities of the food. 

Sniokitn/. — The method of food preservation by 
smoking is really a combination of several methods, 
drying, salting, and chemical. It is said that the 
creosote in the wood smoke to which the food is ex- 
posed serves as an antiseptic. Certain meats and fish 
are preserved by smoking. This hardens the fibers 
and makes them less digestible. 

High Temperature. — Foods may be preserved by 
subjecting them to high temperature. This destroys 
all microorganisms and prevents the decomposition of 
the food. The heating of the food to 140°. F. from 
ten to fifteen minutes is called pasteurization. Heat- 
ing to the boiling-point and subjecting the food to 
this heat for one-half hour or longer is called steriliza- 
tion. It effectively destroys all microorganisms, even 
the spore-bearing bacteria. 

Canning. — Many foods may be preserved for in- 
definite periods of time by sterilization with heat 
and by subsequent storage in hermetically closed 
tin or glass receptacles. Many kinds of meats, fish, 
fruits, and vegetables are at present preserved by the 
process of canning. The food is cut in appropriate 



FOODS 99 

fbrms and placed in tin cans of various sizes. It is 
then covered with hot water and boiled. The cans 
arc covered except for a very small opening at their 
tops, and subjected to a high degree of heat in steam 
boilers for the period of an hour or longer. When 
taken out the opening is sealed with solder, and after 
the cans have again been subjected to heat, they 
are taken out, cooled, labelled, and stored. In this 
condition they may be kept for very long periods. 

If the food in the cans is not properly sterilized and 
if decomposition subsequently sets in, the carbonic 
acid gas developed in the cans causes a bloating or 
bulging out of the top or bottom of the cans, which 
indicates that the food has undergone some decom- 
position. Such cans should be rejected. 

Adulteration. — By adulteration is meant the "alter- 
ing" of the normal composition and consistency of 
the food. Food adulteration is accomplished in vari- 
ous ways: (1) By mixing with the food some foreign 
substance to reduce, lower, or injure its quality and 
strength; (2) by the entire or partial substitution of 
an inferior substance; (3) by the entire extraction of 
a portion of valuable substance from it; (4) by the 
sale of imitations leading the consumer to purchase 
articles he never intended to buy; (5) by the sale 
of food, in part or wholly, of a diseased, decayed, or 
decomposed substance; (6) by coloring, coating, pol- 
ishing, or powdering the food, thus concealing its 
poor quality, or making it look better than it is; (7) 
by introducing into the food a poisonous constituent, 
or any ingredient likely to be harmful to the consumer. 

Advilteration may be harmful, fraudulent, or acci- 



100 HYGIEXE OF FOODS AXD FOOD SUPPLY 

dental. Ilarinful adulteration includes all those which 
are either directly harmful by the addition of injurious 
substances, by the decomposed or unwholesome state 
of a part or the whole of the food, or }\v the diliition 
or extraction of some nutrient j)art of the food, thus 
renderinj]: it less nutritious. lender fradulent adul- 
terations are classed all those which do not directly 
or indirectly harm the consumer, except in deceiving 
him and makiu<j him pay more than he would normally 
lunc ])ai(l. 

There is nnich adulteration of foods in commerce 
and trade. The Federal Food and Drugs Act makes 
stringent provisions against adulteration and mis- 
branding, and much has been done by the Govern- 
ment to insure the purity of foods and the honesty 
of their adulteration. Much more, however, remains 
to be done. The methods of adulteration of foods 
are many and change from time to time. 



MEAT AND MEAT SUPPLY. 

Hygiene of Meat Foods. — ^The hygiene of meat foods 
may be considered according to the following sub- 
divisions: 

Dangers to Health. — Infection by entozoa, bacteria, 
toxins, and ptomains. 

Etiology. — Diseases of the animals, conditions of the 
animals, postmortem changes, postmortem infection, 
adulteration. 

Prophylaxis. — Hygiene of the food animals: meat 
inspection, antemortem and postmortem; hygiene of 



I 



MEAT AND MEAT SUPPLY 101 

place and persons; preservation, sanitary supervision 
of manufacture, etc. 

Dangers to Health. — The dangers to health from the 
ingestion of flesh foods are due to infection by entozoa, 
infections by bacteria, and to the action of toxins and 
ptomains. 

Parasitic Diseases Due to Meat. — These are due to 
(1) infection by tapeworms, (2) infection by trichina, 
(8) infection by echinococci. 

Tapeworms. — The two principal species of tapeworm 
found in man which are due to meat infection are the 
TcBiiia saginata and the Tcenia solium; the former is 
due to infection by "measly" beef, the latter by 
"measly" pork. 

The Cysticercus cellnloscB is the larval form of the 
Tcenia solium. It appears in hogs in the shape of 
minute bladder worms, encased in little cysts which 
are found in the intestines, muscular fibeis, brain, 
liver, and other parts, and especially under the tongue, 
where it may readily be recognized. The cysticercus 
is derived from the segment and egg of the Tcenia 
solium, which are passed from the human intestine 
ingested by the hog, and on reingestion by man develop 
again into tenia. 

The Cysticercns hovis is the larval form of the Tcenia 
saginata of man, and is found in the intermuscular 
fibers and connective tissue of cattle. 

Trichina. — The Trichina spiralis is a parasite 
found mostly in the muscular fibers of pork in the 
form if minute spiral-form worms, which are encap- 
sulated, but may be recognized with the naked eye 
as white specks. The ingestion of i)()rk infected by 



102 HYGIENE OF FOODS AND FOOD SUPPLY 

trichina causes in man the acute disease called "trichi- 
nosis," which is due to the presence of the trichina 
in the muscular fibers. Its symptoms resemble those 
of typhoid fever. The disease is often fatal. 

Kch'inococcus. — Echinococcus sometimes infect sheep 
and, rarely, cattle. The infected meat causes in man 
the hydatid diseases. Originally the infection comes 
from TcBuld echinococcus found in dogs. 

Meat Infection by Bacteria. — Pathogenic bacteria 
may be found in the flesh of animals, and such in- 
fected flesh on consumption is capable of producing 
disease. The ])ath()genic bacteria may originate in 
the diseased condition of the live animals suffering 
from the infectious diseases, or they may gain entrance 
into the meat of healthy animals through infection by 
contact, etc., after killing. 

The diseases of animals infectious to man which are 
caused by pathogenic bacteria and which, it is claimed, 
may be transmitted through their meat to man, are 
the following: Tuberculosis, pleuropneumonia, foot- 
and-mouth disease, cattle plague, anthrax, glanders, 
malignant edema, erysipelas, actinomycosis, typhoid 
fever, cholera, pyemia, septicemia, tetanus, sheep-pox, 
Texas fever, etc. 

Toxins and Ptomains. — Certain meat causes, on in- 
gestion, toxic symptoms. These symptoms are due to 
toxic substances in the meat or to bacterial products 
of decomposition called "ptomains." The s\Tiiptoms 
resemble those of severe gastro-intestinal inflamma- 
tion, and may be fatal. The Bacillus hotnlinus has 
been regarded as the cause of some of the toxic influ- 
ences of certain meats. 



MEAT AND MEAT SUPPLY 103 

The virulence of tlie intoxication by meat differs 
according to the condition of meat, the manner of 
preparation, the quantity ingested, and the individual 
idiosyncrasies of the victim. Intoxication is most 
frequently caused by the eating of "prepared meats," 
such as chopped meats, sausages, canned, "potted," 
and "deviled" meats, etc. 

Causes of the Unfitness of Meat for Food. — These may 
be: (1) The diseases of animals; (2) the unfit condi- 
tion of living animals; (3) postmortem changes; (4) 
infection of the meat by persons or by places of manu- 
facture, sale, etc.; (5) adulteration. 

Diseases of Food Animals.— The diseases of food 
animals, which render their meat totally or partly 
unfit for food, have already been enumerated. 

Condition of Food Animals. — The conditions of the 
food animals, which may render their meat unfit for 
food, are the following: 

1. The death of the animals from age, disease, or 
accident. 

2. ^Moribund conditions from injury, drugs, over- 
work, fright, overdriving, etc. 

'■]. Immaturity: unborn calves and lambs and animals 
in the first few weeks of life, are unfit. 

4. Artificial conditions and treatment of the car- 
casses by blowing up (blown veal), coloring, etc. 

Postmortem Changes. — The temperature, moisture, 
and substances of the slaughtered carcass make a 
favorable medium for the development of micro- 
organisms which swarm in the meat or may gain 
access later. The resulting decomposition and organic 
changes necessarily cause the meat to deteriorate 



104 HYGIENE OF FOODS AND FOOD SUPPLY 

and render it unfit for food unless bacterial action 
is inhibited by placing the meat in a condition ren- 
dering the development of bacteria and putrefaction 
unfavorable. The raj)idity of deterioration de])ends on 
the condition of the animal from which the meat was 
obtained, the cleanliness of the process of preparation, 
and the place in which it is kept. 

Infection hy /Vr.s'o//.<? and Places. — In addition to 
the foregoing sources of deterioration, meat may be 
directly infected with ])athogenic and other bacteria 
by the persons who lumdle it and take })art in slaugh- 
tering, skinning, dressing, cutting, manufacturing, 
and packing. 

Food may also become infected in the various places 
through which the meat must pass in the process 
of manufacture. 

Adulteration of Meat. — Meat adulterations may con- 
sist in: 

1. The addition of foreign substances reducing, lower- 
ing, or injuring the quality of the food. 

2. Partial or entire substitution of an inferior 
substance. 

3. Extraction of some of the valuable substance 
from the meat. 

4. Coloring, coating, or otherwise changing the 
appearance of the food, concealing its poor quality 
or making it appear better than it is. 

Characteristics of Good Meat. — Good meat is uniform 
in color, neither too red nor too pale, firm and elastic 
to the touch, moist but not wet; it does not pit nor 
crackle on pressure, and has a marbled appearance. 
It is free from unpleasant odor, its juices redden 



MEAT AND MEAT SUPPLY 105 

litmus paper slightly. The fat is firm and does not 
run. Beef is bright red, more marbled' than any other 
meat. Veal is pale and less firm to the touch. IVIutton 
is dull red, firm, and its fat white or yellowish. Horse 
meat is coarse in texture, dark in color, without layers 
of fat in the muscles; the fat is yellowish and runs 
down in drops w^hen the carcass is hung up, and has 
a peculiar sweetish odor and taste. 

Preservation of Meat. — Postmortem putrefactive 
changes due to the development of bacteria can be 
prevented: (1) By rigid asepsis and the cleanliness of 
those who handle the meat and by careful attention 
to sanitation in the places in which meat products are 
prepared. This prevents the bacteria from gaining 
access to the meat. (2) By the storage of meat under 
conditions that are unfavorable to the life and devel- 
opment of bacteria. These are cold, dryness, and 
condimental or partly chemical preservations. (3) By 
destruction of all the bacteria, i. e., by sterilization 
of the meat by heat. 

Cold Storage. — Cold storage of meat does not kill 
bacteria, but inhibits their growth, and keeping meat 
in cold storage or freezing may preserve it for a long 
time. The common opinion that meat may be kept 
in cold storage indefinitely without injury is wrong, 
for meat certainly deteriorates if it is kept at a low 
temperature for more than two or three months. 
On thawing, frozen meats deteriorate very rapidly, and 
they have been known to produce toxic symptoms 
on ingestion. As an auxiliary means of preservation 
for not too prolonged periods cold is a valuable 
preservative. 



106 HYGIENE OF FOODS AND FOOD SUPPLY 

Drying. — Drying of meat is an old method of pre- 
serving it, and may be a valuable means of preserving 
the meat fibers; but they should be rendered very dry, 
or in the form of powders. Drying may be accom- 
plished in the sun, and is very slow, or it may be done 
artificially. Its usefulness is necessarily limited. 

Condi uioitdl 7^T.s7Tw//o//.('on(limental preserva- 
tion of meat consists in j)reserving it by the aid of 
salt, sugar, vinegar, and other condiments, either in 
dry form (with salt) or by the wet process (pickling 
in vinegar, etc.). These condiments do not kill the 
bacteria, but they effectively stop putrefaction and 
may preserve certain meats for long periods. 

Smoking. — Smoking meat renders it not only com- 
paratively dry but also impregnates it with the creo- 
sote of the smoke, which serves as a valuable means of 
preservation of certain kinds of meat. 

None of the above methods of preservation destroy 
parasitic ova, or all the pathogenic germs which may 
be in the meat, and all except cold render the meat 
less digestible, and somewhat alter its texture, appear- 
ance, and taste. 

Chemical Preservatives. — The use of chemical pre- 
servatives, such as borax, boracic acid, sulphite of 
soda, and others is very reprehensible, and is justly pro- 
hibited by federal and municipal sanitar}^ legislation. 

The objections against chemical preservatives of any 
food may be summed up as follows : 

1. All chemicals used for preservation are more or 
less toxic, and their ingestion injurious to health, 
especailly if habitually used. 

2. By the use of chemical artificial preservatives 



MEAT AXD MEAT SUPPLY 107 

inferior meats and products and meat which is partly 
decomposed may be so disguised as to be sold as fresh 
and unspoiled products. 

Heat. — Heat preservation of meat is the only 
effective and absolutely reliable method of preserva- 
tion, because it kills and destroys all entozoa and 
pathogenic germs, and thus renders the product sterile 
and absolutely safe. 

For domestic use the sterilization of meat is accom- 
plished by roasting, baking, or boiling for from fifteen 
minutes to an hour. For commercial purposes the pro- 
cess of meat preservation should include (1) destruc- 
tion of all germs by heat, and (2) enclosure of the 
product in hermetically closed sterile vessels in which 
further infection is prevented, thus permitting the food 
product to be preserved for indefinite periods. This 
process of meat preservation consists of "canning," 
and is accomplished in the following manner: (1) 
By selection of appropriate meat; (2) cutting it into 
appropriate pieces; (3) parboiling or exposing the 
meat in hot water under the boiling-point for ten to 
twenty minutes in order to shrink it and lessen its 
bulk; (4) the parboiled meat is placed in cans or tins 
filled with salted soup or liquid and the cover is sol- 
dered on, except for a small aperture for the escape of 
air; (5) the cans are then placed in boilers or steamers 
and subjected to high heat for an hour or two; (6) 
the openings left in the cover of the can are closed and 
the cans are again subjected to a steam bath for an 
hour or more, according to the character of the product. 

Sanitary Supervision, Prevention of Adulteration of 
Meat. — ^The strict sanitary supervision of all the 



lOS HYGIENE OF FOODS AND FOOD SUPPLY 

various processes through which meat })asses from the 
initial to the final j)r()(luct is absolutely necessary in 
order to render the food supply free from dangerous 
contamination and infections. Adulteration by sub- 
stitution, palming off inferior products for superior 
ones, and adulteration with foreign ingredients, as well 
as by artificial ])reservation by means of chemicals, 
may be ])revente(l only by a rigid, thorough, scientific, 
and prompt nuuiicipal and federal inspection by quali- 
fied and competent medical officers. 

Poultry and Game. — The flesh of all domestic fow^ls, 
such as chicken, turkey, geese, duck, and of some 
wild fowls, is used for human food. 

Vacher^ gives the following characteristics of healthy 
poultry and poultry meats: "Healthy poultry are 
active, bright, dry in the eyes and nostrils; the 
feathers are glossy and elastic, and the combs and 
wattles are firm and brilliant red. Age is indicated 
by duskiness of comb and gills, dulness, fading, and 
brittleness of feathers, raggedness of feet and size of 
claws. Good poultry should be firm to the touch, 
pink or yellowish in color, fairly plump, should have 
a strong skin, and a fresh, not disagreeable odor. 
Stale poultry loses firmness, becomes bluish in color, 
green over the crop and abdomen; the skin readily 
breaks, and the bird has a disagreeable odor." 

"Draw^n " or "undraw^n" are terms used to indicate 
the removal or presence of the internal organs of 
poultry offered for sale. Undrawn poultry decom- 
poses sooner on account of intestinal putrefaction. 
Cold-storage undrawn poultry may become dangerous 

^ Food Inspector's Handbook. 



J 



MEAT AND MEAT SUPPLY 109 

to health by its deterioration. As pouhry can he 
obtained at all times there is no good economic reason 
why it should be placed in cold storage for long periods, 
and the practice is reprehensible. The custom of 
keeping poultry or game for a certain time until it 
is "ripe," or "gamey," and partly decomposed, is 
dangerous to health. 

Forced feeding does not seem to produce any 
pathological conditions in poultry, and even the 
"fatty liver" of forcibly confined and fed geese, in 
the much-prized delicacy "pate de foie gras" does 
not seem to affect the gourmand injuriously. Live 
poultry is subject to many and various diseases 
which render the meat unfit for use, and the necessity 
of rigid antemortem inspection is apparent in this 
as well as in other meats. 

Fish Foods. — A large variety of sea and fresh-w^ater 
fish are used for food. Fish are allowed to die by 
being deprived of oxygen. Fish should be used in 
season, should be fresh, firm, and elastic to the touch. 
Fresh fish may be recognized by the rigidity due to 
rigor mortis, the freshness and red color of the gills, 
the moist, clear eye, and not disagreeable odor. 

Frozen fish is not palatable, and decomposes very 
rapidly on thawing. i\Iany cases of poisoning, includ- 
ing ptomain poisoning from eating stale fish, are on 
record. 

The eating of certain shell-fish, crabs, lobsters, and 
oysters is at times fraught witli danger to health, and 
many cases of wholesale poisonings have been reported. 
Oysters sometimes are purveyers of typhoid fever, 
when they are grown near large towns in waters that 



no HYGIENE OF FOODS AND FOOD SUPPLY 

are much contaminated by sewage containing typlioid 
germs. The danger from oysters is the greater in that 
they are very often eattMi raw. 

Fish are preserved by smoking, (h'ying, salthig, 
pickHng, and also l)y canning. 

The sanitation of the estabhsbments where fisli are 
prepared for canning should be the same as that for 
the manufacture of meat jiroducts. 

MILK AND DAIRY PRODUCTS. 

Importance of Milk as a Food.^Of all the various 
foods used by human beings milk is the most im- 
portant. Milk contains all the elements of food 
necessary for the nutrition of man, and it contains 
these elements in a right proportion. Milk is the 
only food of millions of infants and children deprived 
of the breast; it is the principal food of the sick, 
of invalids and convalescents, and it is a part of the 
food of all people at all times. 

The great importance of milk and milk products 
as a food and the magnitude of the milk industry 
make it of paramount importance that they should 
reach the consumer in as clean and as pure a state as 
possible. This, however, is almost impossible for the 
following reasons: (1) Distance, (2) time, (3) the 
nature of the product, and (4) contamination. 

Distance. — In the milk supply of cities the distance 
of the producers from the consumers is necessarily 
great. New^ York City obtains its milk supply from 
about 44,000 farms located in six States and within 
a radius of 400 miles from the city. 



MILK AND DAIRY PRODUCTS 111 

Time. — The city consumer of milk hardly ever gets 
it less than twenty-four hours old, and often thirty- 
six and forty-eight hours elapse between milking and 
consumption. 

Xature of Product. — INIilk, being an opaque animal 
secretion voided at a temperature of the body, is easily 
contaminated with all kinds of impurities difficult of 
detection. 

Sources of Contamination. — These are very numer- 
ous. They may be the cow, the food and water she 
drinks, the stable, barnyard' and surrounding of the 
cow, the pails, cans, and various utensils used by the 
farmer, milkers, and handlers of the milk, and a great 
many other things. 

Character of Impurities. — The impurities which are 
found in milk may be divided under two large groups: 
Dirt and bacteria. 

Dirt. — By dirt is meant everything found in milk 
which is foreign to its composition and is not milk, 
which "is matter out of place." The dirt may be 
mineral, vegetable, or animal. The mineral dirt con- 
sists mostly of dust, sand, clay and earthy particles; 
also of certain preservative salts used for increasing 
the keeping qualities of milk. Vegetable dirt is com- 
posed chiefly of particles of hay, straw, grain, seeds, 
flowers, etc. The animal dirt, which is abundantly 
found in milk, is mostly hair, feathers, manure, insects, 
flies, ova of parasites, etc. 

The amount of dirt found in milk is in direct ratio 
to the care taken in the production of milk. It is often 
very large. Most of the dirt may readily be seen at 
the bottom of vessels after milk has been left standing 



112 HYGIENE OF FOODS AND FOOD SUPPLY 

for some time; it may also be readily obtained by the 
action of the centrifuge. 

Bacteria in Milk. — The most important impurities 
found in milk are bacteria. 

Bacteria are minute vegetable microorganisms, 
invisible to the naked eye, but discernible under the 
microscope, and are found everywhere. Bacteria are 
of various shapes, some round, others spiral, rod- 
shape, etc., and are found clinging to soil, dust, dirt, 
rubbish, ex(;reta, discharges, etc. They develop very 
rapidly under favorable conditions, millions of them 
growing out of one colony. 

The importance of bacterial life lies in the fact that 
to it solely is due the process of putrefaction and 
decomposition, and the disintegration of all organic 
matter. 

Besides their putrefactive action bacteria may also 
play a more important role in the causation and trans- 
mission of disease. 

Within the last several decades it had been definitely 
demonstrated that many diseases, the true causes of 
\vhich were hitherto unknown, were directly due to 
the action of certain bacteria which upon gaining 
entrance into the human body cause certain patho- 
logical lesions resulting in certain groups of symptoms 
which we call by names of various diseases. These 
diseases are usually called ''infectious," because 
they are caused by bacteria and may be transmitted 
from one person to another. 

A large number of infectious diseases are known 
to be transmitted from one person to another by 
means of food and especially milk. 



MILK AND DAIRY PRODUCTS 113 

Disease Bacteria in Milk. — A large number and many 
varieties of disease bacteria may and often are found 
in milk. 

The sources of the disease germs are the cows, 
their surroundings, their food and drink, the persons 
handUng the milk, and the utensils in which it is 
kept, as well as the air with which it may come in 
contact. 

Besides the disease germs themselves milk may be 
contaminated by the common germs of putrefaction. 
These do not cause disease by themselves, but they 
may produce toxic elements in the milk which may 
harm the consumers and cause certain gastro-intestinal 
disturbances and "ptomain" poisoning, often with 
fatal results. 

The infective bacteria which may be transmitted 
by milk are those of the following diseases : Diphtheria, 
scarlet fever, measles, tuberculosis, cholera, typhoid 
fever, dysentery, cholera infantum. A number of 
other infectious diseases have also been transmitted 
by milk, as has been demonstrated at various times. 

Milk and Infants' Diseases and Infant Mortality. — 
The prevalence of gastro-intestinal diseases among 
infants and children, especially during the summer 
months, is well known. Out of a total of 105,553 
deaths of infants in the I nited States during 1905 
not less than 39,399 were due to gastro-intestinal 
diseases. 

The difference in death-rate between breast-fed 

children and those fed on cows' milk in the New York 

Infant Asylum in 1902 was very great: 7.47 per cent. 

in the former to 03.14 per cent, for the latter. The 
8 



114 HYGIENE OF FOODS AND FOOD SUPPLY 

record of Rochester, X. Y., where Dr. Goler inaug- 
urated a vigorous campaign on helialf of clean milk 
for children, proves conclusively how a supply of 
pure milk will nuluce not only the infant mortality 
during the summer months, but also the general death- 
rate throughout the year. 

In New York City the death-rate of children under 
five years was reduced from 9().2 per 1 ()()() during the 
whole year and from \'M\A during the three sunnner 
months in 11)01 to ^h) ])er 1000 during the whole year 
and ()2.7 during the summer months in 1900. This 
reduction is undoubtedly largely due to the cleaner 
milk which is at present supplied to the city and 
especially to the use of the Straus pasteurized milk 
among the i)()()r classes of the city. 

Milk and Diphtheria, Scarlet Fever and Measles. — 
It is not difficult to understand how milk may be 
readily contaminated by the germs of these dreaded 
children's diseases. The farmer's children, or the 
children or employees of the milk dealers and sellers 
may suffer from one of these diseases, and by their 
proximity to the milk, during acts of coughing, spit- 
ting, sneezing, or by the scaling of the skin, may 
contaminate the open cans of milk wdth the infective 
germ and thus transmit the disease to other children 
and people. A large number of scarlet fever and 
diphtheria epidemics have been directly traced to 
infected milk. 

Milk and Typhoid, Cholera and Dysentery. — The in- 
fective germs of the various diarrheal diseases, like 
typhoid, cholera asiatica, and cholera infantum, as 
well as of dysentery, are found in the discharges from 



MILK AND DAIRY PRODUCTS 115 

the bowels of infected persons. These discharges may 
cUng the the hand, clothes, etc., of those who handle 
milk, and thus gain access to the milk in which these 
infective germs find a very favorable medium and 
are capable of developing and increasing in very large 
numbers. The most frequent way in which the germs 
of these diseases gain access to the milk is through 
water. The discharges of infected patients are often 
deposited upon the exposed ground, or in shallow^ 
privy vaults, cesspools, etc., from which they are 
washed off, seep through the ground, and gain access 
to the rivers, lakes, ponds, or w^ells, which serve as 
sources of water supply on farms. 

The typhoid bacillus has been demonstrated in 
milk, and its vitality is so great that it retains its life 
for long periods. Hess reports finding typhoid germs 
in sterilized milk after four months' time. 

According to Whipple (quoted by Ward), "it has 
been estimated that in the United States at the present 
time about 40 per cent, of the typhoid fever in cities 
is caused by water; 25 per cent, by milk." 

Water infected with typhoid fever germs may also 
be used as a washing fluid for milk utensils, or it may 
at times be used as an adulterant. 

Milk and Tuberculosis. — Tuberculosis may be trans- 
mitted through milk because the tubercle bacilli 
which are the cause of the disease may be and are 
often found in milk. Hess found that 16 per cent, of 
the New^ York City milk supply contained tubercle 
bacilli, and according to the investigation of others 
the presence of the germs causing tuberculosis has 
been clearly demonstrated so as to be beyond dispute. 



no HYGIENE OF FOODS AXD FOOD SiPrLY 

Where do the tubercle gjerms which are found in 
milk come from? There is no doubt that some of these 
germs may come from accidental contamination from 
the outside. It is easy to see how persons who are 
afflicted with the disease may, while handling]: the milk, 
infect it with tubercle bacilli by couijhing, s])itting, 
sneezing; or the germs may be found in the dried 
dust floating around dairies, or on the hands and 
clothes, etc., of the persons handling the milk. 

There are also strong reasons for believing that a 
large or a considerable number of the tubercle germs 
found in milk are derived from the cow herself. Un- 
questionably a very large percentage of milch cows 
suflVr from tuberculosis. According to many observers 
the average percentage reaches at least 25 per cent. 
This means that one cow in every four is affected . 
The disease is scattered over the entire country and 
there is hardl\' a herd that is completely free from its 
ravages. 

The question whether a tuberculous cow gives milk 
containing tubercle germs has been decided affirma- 
tively, at least insofar as it is now definitely known 
that cows suffering from advanced tuberculosis which 
involves the udder yield tuberculous milk. 

COWS' MILK. 

Definition. — Milk is the lacteal secretion obtained 
by the complete milking of one or more healthy cows. 

Composition. — Milk consists of w^ater in which cer- 
tain solids are disolved or suspended. The relative 
proportion of the solids to the w^ater varies from 



COWS' MILK 117 

11 to 14 per cent., to 86 to 89 per cent., with an average 
composition of 13 per cent, solids and 87 per cent, 
water. 

Solids. — The niilJx solid.'f consist of sugar, fat, 
proteids, and minerals. Milk also contains a certain 
amount of ferment, gas, and bacteria. 

MUk-sugar (Lactose). — Lactose is a sugar peculiar 
to milk, found in milk only, and differing somewhat 
from sugrose, dextrose, and other sugars. Milk-sugar 
is less sweet, less soluble, less subject to acid fer- 
mentation, has a specific gravity of 1.53, is soluble in 
6 parts of cold and 2.5 parts of boiling water; under- 
goes lactic acid fermentation readily, but alcoholic 
with difficulty (Blyth). The average percentage of 
milk-sugar in milk is about 5, varying but slightly from 
this. 

Milk-fat. — IMilk-fat consists of the glycerides of 
various fatty acids, volatile and non- volatile. It is 
found in the milk in the form of an emulsion consist- 
ing of very numerous minute fatty globules held in 
suspension in the whole milk. 

The milk-fat is the most variable part of the milk 
constituents. Its proportion varies between 2 and 6 
per cent., with an average of 4 per cent. 

Proteids and Alhnmivoids. — The proteid matters in 
milk consist of about 80 per cent, of casein and 20 
per cent, of other albumins, such as lacto-albumins, 
protein, nuclein, etc. 

The casein is the principal and most valuable pro- 
teid matter. Casein is coagulated by acids, by gastric 
juice, by rennet, and by a variety of other substances; 
it is not precipitated or coagulated by heat which does 



118 HYGIENE OF FOODS AXD FOOD SUPPLY 

coagulate the lacto-albuinius. The ])r()|)()rti{)ii of pro- 
teid matter in milk is less variable than that of fat. 
Its average is 0.2,") ])er cent. 

MinrrdJ Matter. — Milk contains various minerals 
in minute quantities. Milk-ash shows the ])resence of 
potash, soda, lime, magnesia, chlorine, iron, certain 
acids, etc. The ])ercentage of mineral matter in milk 
averages 0.7."). 

Composition of Average Milk. 

Water . . . S7 per rent. 

Solids . . \'i per cent. Sugar . o.OO per cent. 

Fat . . 4.00 per cent. 

Proteid . . . 3.25 per cent. 

Mineral . . 0.75 per cent. 

13.00 per cent. 

Ferments and Gases in Milk. — Milk contains a 
number of ferments or enzymes (diatose, galactose, 
etc.) which are peculiar to every species of animals 
and have some function in the digestion and nutritive 
qualities of the milk. 

Milk when fresh also contains some gases, such as 
oxygen and carbon dioxide, due to the air it contains. 
Later the pressure of carbon dioxide may be due to 
fermentation. 

Appearance, Color, and Reaction. — Normal milk has 
a white or slightly yellowish color; it is opaque, has a 
a pleasant characteristic odor, and a sweetish taste. 

The reaction of milk is ''amphoteric," i. e., slightly 
acid to litmus and alkaline to turmeric. The reaction 
becomes more acid with the advance of lactic acid 
fermentation; when milk becomes decomposed it 
develops ammonia and becomes alkaline in reaction. 



COWS' MILK 110 

Specific Gravity. — Tlie weight and density of milk 
are greater than of water, inasmuch as most of the 
milk solids are of a relatively greater w^eight and 
density than water. 

The heavier and denser solids are the milk-sugar, 
the proteid matter, and the mineral matter. Milk- 
sugar, specific gravity 1.55, proteids 1.20 (Rubner). 
The only ingredient of milk w^hich is lighter and less 
dense than water is the milk-fat (0.92). 

If a liter of water at ()0° F. (15° C.) weighs 1000 
grams, a liter of milk at the same temperature will 
weigh from 1028 to 1032. The specific gravity of 
average milk is usually 1.029, with variations from 
1.028 to 1.032. 

Milk without fat (skim milk) will have a much 
greater specific gravity, for the lighter part is w^ith- 
drawn. The specific gravity of skim milk ranges 
from 1.035 to 1.040, according to the more or less 
thorough removal of the fat. 

The specific gravity of milk is increased by low^ 
temperature, by the addition of solids, and by the 
substraction of fat. It is decreased by high tem- 
perature, by the addition of water, and by the addition 
of fat. 

Variations. — Not only the quantity but also the 
quality and the relative amounts of the various milk 
ingredients vary greatly. Some of the factors on 
which the variation depends are the breed of the 
cow, age, kind, health, condition, care, food, drink, 
housing, treatment, climate, time of year, time of 
day, period of lactation, season, weather, and many 
others too numerous to mention. Most of the varia- 



120 HYGIENE OF FOODS AND FOOD SUPPLY 

tions produced by tliese factors arc normal and are 
expressed in the relative quantity of milk j)roducc(i, 
or the relative proportion of its various ingredients. 
Among the most important variations in milk are 
those which are found in colostrum, fore-milk, and the 
strippings. 

Colostrum. — For a certain j)eriod before and for 
several days after parturition the milk secreted by 
the cow differs materially in composition from nor- 
mal milk. While most cows *'dry up" or cease to give 
milk in the last months or weeks of ])regnancy there 
are some which continue to produce milk until the 
last days of pregnancy. During the ten days or two 
weeks before calving and from three to five or six days 
after the milk derived from cows is called "colostrum," 
or commonly "bee stings." 

Colostrum differs in composition from normal milk 
in that it contains a relatively smaller percentage of 
water (about 75 per cent.), relatively less milk-sugar 
and milk-fat, and relatively more protein matter, 
not in the form of casein but of lacto-albumin. To 
the latter it owes its property of coagulation by slight 
heat, a distinctive characteristic of colostrum. Colos- 
trum also contains a considerable number of blood 
corpuscles and of the so-called "colostrum corpuscles." 

The color of colostrum is distinctly yellowish and 
reddish, the taste peculiarly sweetish, and the odor 
specific. The ingestion of colostrum, especially when 
heated, is relished by a number of persons, although 
it has been known to cause gastric disturbances. The 
mixing of colostrum with the rest of the milk, or its 
sale, is forbidden by most municipalities. 



COWS' MILK 121 

Fore-milk and Strippings. — Tliere is a considerable 
difference in tlie relative amount of milk-fat in the 
few streams of milk derived at the beginning of milking 
from that of the few streams of milk derived at the 
end of the milking. The first milk, called fore-milk, 
contains sometimes less than 1 per cent, of fat, while 
the last, called strippings, contains sometimes over 5 
per cent. 

Abnormal Milk. — Milk is sometimes abnormal in 
color, composition, etc., and the sale of such milk is 
usually forbidden. 

Milk may be abnormal in color, distinctly red, blue, 
yellow, violet, etc. These abnormal colors of the milk 
are due to contamination with specific bacteria, which 
produce the changes in color. 

The odor and taste of milk may also be abnormal. 
Thus milk sometimes is distinctly bitter or has the 
taste of garlic, onions, turnips, cabbage, etc.; it may 
bear some of the characteristic odors of strong vege- 
tables, etc. Milk may also have a distinctly fermenta- 
tive and "swilly" taste. Most of these deviations from 
the normal are due to the food ingested by the cow. 
The bitter taste may be due to bacterial action. 

Milk may be abnormal in its consistency and become 
"slimy," "ropy," and viscous. In this condition it 
will not churn, nor will the cream separate, but other- 
wise it does not seem to be very harmful. The condi- 
tion is due to the action of certain bacteria. Kopy 
milk is said to be a favorite article of food in Norw^ay 
and elsewhere, and may be artificially produced by 
immersing the stem of "butterwort" in milk (Hlyth). 



122 HYCIEXE OF FOODS AXD FOOD SUPPLY 

MILK PRODUCTS. 

A consideration of milk j)r(>(ln('ti()n and inspection 
is inc()nij)lete withont reference to the most important 
prodncts wliicli are a part of the milk indnstry. The 
milk products are the following: (ream, skim milk, 
butter, buttermilk, cheese, whey, condensed and evap- 
orated milk, milk powders, koumiss, kefir, etc. 

Cream. Cream is the fatty j)orti()n of milk. It has 
the same composition as milk except that the i)ercent- 
aji^e of fat is very nuich lar<^er. I'he })ercentage of 
cream in milk may vary from (> to 50 or 60, and de- 
pends upon the process of obtaining it from the milk. 
The a\-erage amount of butter-fat in cream is 20 per 
c(Mit.; tlic Fiiitcd States standard is IS per cent. 

Production of Cream. — Cream is found in milk, in 
suspension, in minute globules of varying size. It is 
separated from milk by two processes: the gravity 
method and by aid of the centrifuge. 

Separation by aid of gravity is the oldest known 
process of gaining cream. It is based upon the fact 
that the suspended fat globules are of a lesser specific 
gravity than milk and rise to the surface w^hen the 
whole fluid is left at rest. The common method is to 
pour the new^ly draw^n milk into vessels and let them 
stand for a period of twenty-four to thirty-six hours. 
The cream rises to the surface and appears as a yel- 
lowish layer, and may be accordingly removed from 
the milk. Gravity methods may be divided into 
two, the shallow-pan and the deep-vessel setting 
systems. 

Cream is also separated by centrifugal force in 



MILK PRODCCTS 123 

special *'sei)arat()rs," which remove all fat except 0.1 
per cent., which is left in the skim milk. This is an 
effective process of separation. 

Skim Milk. — Skim milk is milk from which all or 
part of the cream has been removed. The amount 
of fat remaining in skim milk depends upon the 
methods of separation and the thoroughness by which 
it is done; it may vary from less than 0.1 per cent, 
to more than 1 per cent. Skim milk has a white 
and somewhat bluish color, a high specific gravity 
varying from 1.035 to 1.040. Because of the proteid 
and casein it contains, skim milk is a highly nutritious 
and valuable food. The sale of skim milk is prohibited 
in many cities, not because of any harm that it may 
do, but mainly on account of the ease with which it 
is substituted for a whole milk and the difficulty of 
detecting the adulteration. The casein may be sep- 
arated from the skim milk and used for commercial 
purposes, or it is used for the extraction of its milk- 
sugar. Certain forms of cheese are largely made of 
skim milk. 

Blended Milk. — This term is applied to a modified 
milk in which one or more of the components of milk 
is increased or diminished so as to furnish a modified 
milk with definite desired stated percentages of certain 
of the milk comj)onents. It is largely used for infant 
foods, and manufactured according to formula' pre- 
scribed by physicians. 

Milk Products. — These are used chiefly as infant 
foods and are prepared by complete slow evaporation 
of the water of the milk. As a rule the powders are 
mixed with some sugar and cereal products. 



124 HYGIENE OF FOODS AXD FOOD SUPPLY 

Condensed Milk. — Condensed milk is a milk from 
which a lar<;e part of the water has been extracted 
by slow e\a])()rati()?i. It is a \cry important article of 
commerce. Most of the condensed milk sold contains 
about 70 to 72 per cent, of water with 2S to .'^0 per 
cent, of milk solids, to which cane-sii«;ar is added to 
increase the keeping qualities. Some thickeners may 
also be used to give the condensed milk more "body." 
The condensed milk is sterilized and sold in hermeti- 
cally sealed tin cans. When mixed with water it has 
a sweet, cooked taste. 

Butter. — Butter is the milk-fat of the milk gathered 
into a mass and separated from the milk or cream 
by the process of churning. Besides the milk-fat which 
it contains in the proportion of 80 or more per cent., 
butter also contains water and minute quantities of 
the other ingredients of milk. 

Butter is commonly made of cream which is for this 
purpose ripened or made to undergo a process of 
lactic acid fermentation which is supposed to give the 
butter its valued "flavor." A "starter" made of 
buttermilk or sour cream is used to produce the 
"ripening." 

Butter is produced by churning or agitating the 
cream with paddles or spoons, in vessels, tubs, or 
barrels. These may be revolved by hand or machine 
power. The particles of fat adhere together and form 
distinct grains w^hich are worked over, the buttermilk 
is removed by several w^ashings of water, and the whole 
turned into a mass by w^orking and pressing together. 
The process of butter-making requires attention to 
temperature and other factors, upon which the flavor 



MILK PRODUCTS 125 

and (luality of the butter depend. Some salt is added 
to tlie butter. 

Buttermilk. — Buttermilk is the residue left after 
butter is made from milk or cream. It contains all 
the ingredients of milk except fat. It contains millions 
of lactic acid germs, and is a valuable food for man 
and animals. 

Cheese. — Cheese is "the solid and ripened product 
made by coagulating the casein in the milk by means 
of acids or rennet." 

Cheese is made of whole milk which has undergone 
some lactic acid fermentation. It is then coagulated 
or rendered into two parts: one, an insoluble semi- 
solid composition consisting of the casein and fat, and 
the other of water (92 per cent.), of nearly all the 
sugar, of the albumin and the mineral matter. The 
insoluble part is then pressed out of the water and 
worked over by pressing and cutting, as well as by the 
addition of certain ferments, until the desired flavor 
and texture of the finished product is obtained. 
Cheese may be made of whole milk, of skim milk, 
and of milk to which cream has been added. The 
"rennet" which is added and used for the coagulation 
of the milk is an extract made from the fourth or 
digestive stomach of a young calf fed on milk. 

There are many varieties and forms of cheese, 
depending upon the kinds of milk, temperature of 
fermentation, degree of acidity, manner of coagula- 
tion, kind of rennet, ])r()cess of ripening, the specific 
"ripening" bacteria used, etc. 

The liquid ])orti()n which is left after the insoluble 
part has been removed in the process of cheese-making 



12() HYGIENE OF FOODS AND FOOD SUPPLY 

is called whey. It consists mostly of water, but 
contains small quantities of albuminous matter and 
the sugar and most of the mineral nnitter of the milk. 
Whey is used for the extraction of milk-sugar, and is 
also a valuable food for domestic animals. 

The casein of the milk which is extracted from skim 
milk is also used for various ])ur|)()ses in the commer- 
cial nuimifacture of sizing for paper, etc. 

Standards. The relative c()nij)()siti()n of milk and 
some of its ])roducts gi\-en above are only the aver- 
age composition, found after an examination of a 
great number of sam])les of milk, etc., with large 
variations in the relative composition. In order, 
h()we\'er, to guard the welfare of the public and pre- 
vent substitution, adulteration, and selling inferior 
grades of products, municipalities, States, and the 
federal government have instituted certain minima of 
compositions or standards below which milk and its 
products must not go and must not be sold to the 
public. 

Solids. Fat. Solids not fat. Water. 

Per cent. Per cent. Per cent. Per cent. 



Milk . . . . 


11.75 


3.25 


8.5 


88.25 


Skim milk 


9.25 








Condensed milk . 


28.00 


7.00 




72.00 


Cream . 




18.00 






Butter . . . 




82.50 






Cheese . . . 




50.00 







The New York State standard for milk was 12 per 
cent, solids and 88 per cent, water until 1910, when 
it was lowered by act of Legislature to 11.5 per cent, 
solids and 88.5 per cent, w^ater. 

The New York City standard for milk is 12 per 
cent, solids, of which 3 per cent, must be milk-fat. 



MILK PRODUCTS 127 

Other States and cities have sHght variations from 
these standards. 

"Standards are based upon data representing mate- 
rials produced under American conditions and are 
fixed as such that a departure from above or below 
the minimum limit they prescribe is evidence that 
such articles are of inferior quality. The limits fixed 
as standards are not necessarily the extremes authen- 
tically recorded for the articles in question, such 
extremes being due to abnormal conditions as a 
rule." (Wiley.) 

Official Definitions. — The following are the official 
definitions of milk and its products according to the 
United States Department of Agriculture : 

Milk. — Milk is the fresh, clean lacteal secretion 
obtained by the complete milking of one or more 
healthy cows, properly fed and kept, excluding that 
obtained within fifteen days before and ten days 
after calving. 

Blended Milk. — Blended milk is milk modified in 
its composition so as to have a definite and stated 
percentage of one or more of its constituents. 

Skim Milk. — Skim milk is milk from which a part 
or all the cream has been removed. 

Condemcd or llvayorated Milk. — Condensed or 
evaporated milk is milk from which a considerable 
portion of water has been evaporated. 

IhdtermUk. — Buttermilk is the product which re- 
mains when butter is removed from milk or cream in 
the ])rocess of churning. 

(h'cani. — Cream is that portion of milk, rich in milk- 
fat, wliicli rises to the surface of milk on standing, 
or is separated from it by centrifugal force. 



128 HYGIENE OF FOODS AND FOOD SUPPLY 

Butter. — Butter is the clean, non-rancid product 
made by ^^atlierin*:: in any manner tlie fat from fresh 
or ripened milk or cream into a mass, whicli also 
contains a small j)()rtion of tlu^ other milk constituents, 
with or without salt. 

Chcrsr. — Cheese is the sound, solid, and ripened 
j)roduct made from milk or cream hy coagulating the 
casein thereof with rennet or lactic acid with or with- 
out the addition of ripenin<c ferments and seasoning. 

Whey. — Whey is the product remaining after the 
removal of fat and casein from the milk in the process 
of cheese-making. 

Koumiss. — Koumiss is the product made by the 
alcoholic fermentation of cows' or mares' milk. 

Kefir. — Kefir is a product made b\' a specific yeast 
fermentation of milk. 

MILK ADULTERATION. 

Milk is adulterated in several ways: (1) By addi- 
tion of water; (2) by subtraction of cream; (3) by 
both addition of water and subtraction of cream; 
(4) by addition of coloring matter, thickeners, and 
certain harmless substances; (5) by addition of skim 
milk; (0) by addition of chemicals as preservatives. 

Addition of Water. — This is one of the most prevalent 
methods for the adulteration of milk. It is so easy, 
apparently difficult of detection, and changes the ap- 
pearance and general physical quality of the milk so 
little that it is often resorted to by dishonest dealers 
and producers. The addition of water to milk reduces 
its quality by diluting it, and the whole mass is less 



MILK ADULTERATION 129 

nutritious and has fewer food ingredients than normal 
milk. This is a harmful adulteration because it reduces 
the quality of the milk, and when fed to children 
j)r()ves injurious to their health. It is also a fraudulent 
adulteration because it substitutes an inferior product 
for the same price that the superior would sell for. 

Extraction of Cream. — The extraction of cream, or 
what is called '' skimming," is also a frequent mode of 
milk adulteration. It is perhaps even more in vogue 
among dealers than simple watering, because it is so 
much more profitable and difficult to detect. A 
forty-quart can of milk which sells for $1.60 will bring 
the dealer but 16 to 20 cents of additional profit w^hen 
he adds four or five quarts of water to the can. If, 
however, the dealer removes two quarts of cream of 
the six or seven which the can contains he gains the 
price of the two quarts of cream (40 to 60 cents) less 
the price of the two extracted quarts, which amount 
to only 8 cents. This shows that the skimming of 
milk is a very profitable procedure, even w^hen it is 
but partial. Indeed, a great deal of the milk in cans, 
which is sold at the markets and by grocers for a low^ 
price, is more or less skim milk. 

Skimming and Watering. — Skimming of milk makes it 
heavier by subtraction of the fatty or lighter portion, 
thus increasing its specific gravity and density. A 
skim milk will read from 32 to 38 on the Quevenne 
lactometer and from 1 10 to 118 on the Board of Health 
lactometer, according to the amount of cream taken 
off. In order to disguise this higher specific gravity 
and to reduce it, dealers who make their own tests 
add sufficient water to reduce the density of the 
9 



130 HYGIENE OF FOODS AND FOOD SUPPLY 

skim milk, so as to make the readings on the lac- 
tometer about the normal, and thus try to deceive 
the inspector who rehes too much on the lactometer 
examination alone. 

Skinnnin<]:, as well as skinnnin.u- and watering, 
reduces the nutritive (juahty of the milk and is a 
harmful as well as a fraudulent adulteration. 

Addition of Skim Milk.- The addition of skim milk 
to normal milk reduces the quality of the whole milk 
and is harmful as well as fraudulent. One of the 
princij)al reasons for the ])rolnl)iti()n of the sale of 
skim milk in some cities is the tendency of dealers 
either to sell skim milk for whole milk, or to reduce 
whole milk by the addition of the skimmed. 

Addition of Coloring Matter and Other Harmless 
Ingredients. — The addition of coloring matter is mostly 
practised to disguise the poor appearance of skim or 
watered milk and make it look richer. The coloring 
matter most commonly used is a vegetable coloring 
"annatto." 

The other colors used belong to the coal-tar family 
(azo-colors) and are harmful in comparison to coloring 
with "annatto," which is harmless. Their detection is 
possible only by chemical tests. 

Sodium bicarbonate is sometimes added to milk 
which is beginning to turn sour, in order to disguise 
the acid taste. In small quantities the addition of 
soda is harmless, but the procedure is dishonest in 
that its purpose is to palm off milk which is acid for 
fresh milk. 

Thickeners are very seldom put into milk, more 
frequently into cream and condensed milk. 

Addition of Chemicals. — See p. 140. 



MILK PRESERVATION 131 

MILK PRESERVATION. 

Milk Deterioration. — The milk secretion of normal 
cows remains in a normal state for a comparatively 
short period, and important changes occur very 
soon. 

If left undisturbed at the normal house tempera- 
ture fresh milk shows some physical changes within 
six to twelve hours, and by this time it has also passed 
through certain chemicobiological changes. The 
physical changes are limited to the separation of the 
fat globules and the separation of the cream layer at 
the upper portion of the vessel containing the milk. 
There is also a reduction of the temperature of the 
milk from that at which it was voided to the tem- 
perature of the room. The other changes which occur 
are a souring which is slight at first and later increases. 
If milk is left at the same temperature for longer 
periods a distinct coagulation or curdling develops, 
owing to the hardening and separation of the casein. 
At the same time there is some gas formation and a 
bitter taste in the milk may become noticeable. All 
these changes are included in the term *' deterioration" 
of milk. These phenomena are only the outward and 
noticeable changes; the real physical, chemical, and 
biological changes are, of course, more complex, and 
cannot be so easily detected. To what are these 
changes in the milk due? 

Causes of Deterioration. — The se])arati()n of the cream 
is easily accounted for by the comparative lightness 
of the fat globules which coalesce and rise to the 
top. The other notcMl changes are due to the micro- 



1)32 HYCIESE OF FOODS AM) FOOD SUPPLY 

orpuiisnis. A perfectly sterile milk, that is, one abso- 
lutely free from bacteria, has never l)eeii obtained. 
Microorganisms are found in the ducts of the teats 
and udder of the cow, and even milk obtained by 
cannula already contain a certain luunber of ^ijerms. 
Inunediately after secretion the milk begins to be 
contaminated with innnerous germs from the air 
in the stable, the hands of milkers, the udder and 
teats of the cow, the surfaces of strainers, pails, etc., 
so that by the time the milk is taken out of the stable 
it contains a very large number of bacteria. The 
number of bacteria usually remains stationary for a 
few hours owing to the so-called " germicidar' power 
which the milk j)ossesses at this initial stage of its 
existence outside the cow. Sooner or later, according 
to the condition of temperature, the bacteria begin 
to develop and multiply, so that after a certain time 
they are so numerous as to be counted by the million 
in the cubic centimeter. 

The number of the bacteria is not the most impor- 
tant factor, but their importance lies in the kinds of the 
multiplying germs. These bacteria which get into and 
develop in milk are of several kinds. 

In the first place there is the group of germs named 
"lactic acid" bacteria. By acting upon the lactose 
they convert it into lactic acid and thus favor the 
gradual souring w^hich on reaching a certain stage 
causes coagulation of the casein with consequent 
curdling of the milk. Another group is composed of 
the "gas-forming" or "aerogenous" bacteria which are 
said to cause the gas formation in deteriorated milk. 
The butyric- and proteid-decomposing bacteria may 



MILK PRESERVATIOX 133 

also develop simultaneously with the lactic acid 
germs. There are numerous other germs which may 
at the same time act upon the milk. The lactic acid 
bacteria are important because they cause the souring 
of the milk and its subsequent curdling. As far as 
health and food value are concerned, lactic acid for- 
mation is not necessarily a harmful process. The 
ingestion of even very large quantities may not be 
harmful to health; indeed, in many cases it is even 
beneficial. Buttermilk and whey contain enormous 
quantities of the lactic acid germs, but are drunk with 
profit to health. They also possess another beneficial 
action in that they counteract other more harmful 
bacteria. While lactic acid fermentation is active and 
at its height, it is germicidal to other bacteria, which 
cannot develop in an acid medium. In may there- 
fore be said with truth that the lactic acid fermenta- 
tion process is not per se a harmful process. 

The gas-producing, the butyric- and protein-decom- 
posing germs are of more importance to health, because 
they are of harmful character. They produce putre- 
faction and decomposition, they develop a bitter taste 
and foul odors, and may also produce certain toxins, 
which may become very harmful to those ingesting 
the fluid. 

Conditions Favoring and Retarding Bacterial Growth 
in Milk. — In view of the rapidity of the growth and 
the various characters of bacteria, it is important to 
note the conditions which favor and retard their 
growth and development. Cienerally, low tempera- 
tures, very high temperatures, absohite dryness, and 
certain chemicals are unfavorable to the life and growth 
of germ life. 



134 HYGIEXE OF FOODS AXD FOOD SUPPLY 

i\Ioistiire and a temperature between 00° and 100° 
F., on tlie other hand, are very fa\'()ral)le. 

Dryness. — Moisture is necessary for <i:erni hfe, 
and bacteria develop very slowly, if at ;dl, in a dry 
medium. It is, of course, diflicult to obtain absolute 
dryness, which alone is inimical to bacterial life, but 
if milk is dried and kept in the form of a j)owder it 
may be preserved for some time, although this applies 
rqore to milk-powder from skim milk tlian to powdered 
wliole milk, as the cream is said to become rancid if 
in ])()W(ler form. 

Jj)ir Trill pcrafurc. — By low temperature is meant 
any temperature between 00° F. and the freezing-point. 
A low temj)erature does not destroy, })ut stops growth 
and development of bacteria. Their number remains 
the same, but they are in stunned form, always cap- 
able of doing mischief, even under these conditions. 
Thus it is known that typhoid fever bacilli may be 
alive for long periods even in ice or frozen milk, and 
such milk may therefore produce the disease. While 
bacteria do not grow" in frozen milk, they do grow in 
milk kept at temperatures between 34° and 50° F., 
but only very slowly. The varieties which grow at 
these low temperatures are not the lactic acid bacteria, 
but those w^hich are likely to do harm if the milk is 
kept too long at these temperatures. Milk kept at 
temperatures between 34° and 50° F. may be preserved 
for several days to a week and more, the lower the 
temperature the longer. The milk will not become 
sour, but it may become unfit for use because of 
the development of the other bacteria and their 
products. 



MILK PRESERVATION 135 

Mean T luperaturc. — Tlie effect upon milk kept at 
temperatures between 50° and 100° F. varies accord- 
ing to the degree of temperature and depends upon 
the kind of bacteria wliich the temperatures favor in 
growth and development and multiplication. 

Various bacteria have a different and varying point 
of thermal death, as well as a temperature at which 
growth and development are most abundant. Lactic 
acid bacteria, for instance, develop most rapidly at a 
temperature of 60° to 70° F., at which they multiply 
more quickly than any other species. As their devel- 
opment is inimical to the growth of other germs, 
milk kept at 60° to 70° F. will sour and contain lactic 
acid bacteria to the exclusion of almost all others. 
At the higher temperatures between 80° and 100° F., 
the lactic acid bacteria do not always gain a pre- 
dominance, but often others, especially the gas-pro- 
ducing bacteria, gain the upper hand and then in 
addition to the acid bacteria the milk contains other 
less desirable germs. 

High Temperatures. — High temperatures, i. e., tem- 
peratures above 100° F., are inimical and unfavor- 
able to the life and growth of bacteria, and the various 
bacteria have their own thermal death-point. Some 
are destroyed at temperatures of from 120° to 140° F., 
kept u]) for a certain period ; to destroy others requires, 
for an hour or more, a temperature above the boiling- 
point of water. Fxcept for a few species, bacteria 
cease growing when the temperature is raised above 
100° F. and begin to die when it is above 120° to 140° 
F., according to time of exposure to heat. At higher 
temperatures the bacteria are more quickly destroyed 



130 IfVCIENE OF FOODS AND FOOD SUPPLY 

and in less time. Bacteria which bear spores are the 
most (Hfficult to kill, and sometimes must be subjected 
to a \ cry high temperature for a long time before they 
are destroyed. Most of the active germs, including 
the j)atliogenic bacteria of most connnon diseases, like 
typhoid, dii)htheria, and tuberculosis, are killed at 
temj)eratures of 140° F. kept up for twenty minutes, 
and at higher tem])eratures kept u]) for less time. 

Chofiinil.s'. — Certain cluMnicals are inimical, to bac- 
terial Hfc and growth, ahhongh the luunbcr of these 
chemicals api)licablc to milk is, comparatively, very 
small (see page 141). 

Milk Presermtimi by Cold. — As previously indicated, 
cold, /. e., a temperature of from 32° to 50° F., does 
not destroy the germs in milk but merely inhibits and 
stops their growth and nniltij)lication and thereby' 
keeps the milk from becoming sour and decomposed. 
The length of time for which milk may be preserved 
by cold depends upon the number and the kind of 
germs originally in the milk before its temperature 
was reduced. It may vary from twenty-four hours 
to a Aveek; frozen milk has been known to keep for 
longer periods, and is an article of commerce in Siberia 
and other northern countries. While the souring of 
the milk is undoubtedly postponed, it is not certain 
that its decomposition by other bacteria is avoided. 
Thus milk kept under low temperatures may keep 
sweet, and yet at the same time develop dangerous 
qualities. The main advantages of cold as a preserva- 
tive are that it does not change the appearance and 
composition of the milk, and is valuable as an aid in 
preserving clean milk for a moderately short time. It 



MILK PRESERVATION 137 

must always be remembered that none of the germs 
are killed by cold temperatures and that the patho- 
genic bacteria may be as active as in warmer raw milk. 
Infected milk is therefore a dangerous milk to drink 
while raw, even if kept in a cool state. Cold is only a 
valuable aid in milk ineservation, nothing more. 

Milk Preservation by Sterilization. — Sterilization is 
the only method by which it is possible to make abso- 
lutely certain that milk contains neither bacteria nor 
their spores. It is the only method of preservation 
which rids milk of pathogenic bacteria. 

Sterilization is defined as the "heating of milk to the 
boiling-point of water and above for a time sufficient 
to destroy all organic life and all bacteria and their 
spores." 

Complete or absolute sterilization cannot be accom- 
plished unless the milk is heated well above the boiling- 
point — 220° to 240? F. — in autoclaves or sealed cham- 
bers under steam-pressure for a prolonged time, varying 
from one-half to two hours. This is the only means 
which assures complete destruction of all spores 
and pathogenic spore-bearing bacteria, like those 
of tetanus, etc. Simple boiling is also sometimes 
called sterilization. While this kills most germs and 
even a few spore-bearing germs, it does not make 
certain that all spores have been killed. 

The objections to sterilization of milk, complete as 
well as incomplete, by boiling, are that certain changes 
are produced in milk by the heat. The effects of boil- 
ing and sterilization are as follows: 

1. Change in color due to the browning or carameli- 
zation of the lactose. 



13S HYGIENE OF FOODS AND FOOD SUPPLY 

2. rhaii<]:e in taste, tlio milk rocoiviiit^ a different 
cooked taste. 

'A. The destruction of all lactic acid bacteria, fer- 
ments, enzymes, as well ;is all other ii:erms in the milk. 

4. Coa^nilation of the albuminoid matter in the milk. 

The sum of these chan«,'es is that the milk is not 
only less tasty, but is nmcli less ditj^estihle and fit 
for food. Vov infant-feeding it has been found not 
ai)j)roj)riate, and some observers claim that it may 
cause scur\y and rickets. 

Milk Pasteurization. The word "pasteurization" has 
been so nnich used and missused that it is about time 
to discard it entirely, for it has no intrinsic meaning 
and simj)ly confuses the minds of those who use it 
promiscuously. Pasteur's name is applied to a process 
which is carried out in many and various ways, and 
not always with scientific accuracy. The official 
definition of the term is ''the heating of milk to a 
degree of heat sufficient to kill all most active germs; 
in general, the word is applied to any kind of heating 
of milk short of boiling. It is obvious that until a 
definite attempt is made to define the degree of heating 
and the time of heating and the exact procedure, the 
term will embrace various meanings, according to the 
whim and methods of each commercial or other concern 
using it. 

As Rosenau says: "We should protest against a 
w^ord w^hich means a generality." And as he further 
remarks, the two main dominant factors that control 
the temperature and time at which the milk should 
be pasteurized are (1) "the thermal death-points of 
pathogenic bacteria, and (2) the ferments in the milk.'* 



MILK PRESERVATION 139 

The aim and purpose of so-called pasteurization is (1) 
to kill all most active bacteria, especially pathogenic, 
(2) to leave the ''ferments" unafl'ected, and (3) to 
change the milk as little as possible in its general 
appearance, taste, and digestibility. There is as yet 
no unanimity of opinion as to the degrees and time 
at which these conditions are reached. According to 
Rosenau a heating of milk for twenty minutes at a 
temperature of 140° F. absolutely destroys the tubercle 
bacilli, typhoid, diphtheria, dysentery, cholera, and 
other germs, but not all the necessary and valuable 
ferments in the milk. Not only the bacteria but their 
toxins, especially those of diphtheria and tetanus, are 
likewise destroyed at such a heating. There are, how^- 
ever, certain spore-bearing bacteria and bacterial toxins 
which remain unaffected at these temperatures. These 
spore-bearing germs are fortunately rare. 

Chemical Preservation. — The difficulty of keeping 
milk sweet for a shorter or longer time after milking, 
led to the use of chemical preservatives. Among 
those formerly used are borax, boracic acid, salicylic 
acid, peroxide of hydrogen, and formalin. At present 
the use of any chemicals for milk preservation is 
strictly forbidden, although it is still more or less 
practised in secret. Borax and boracic acid were 
used in quantities of ten grains to the quart of milk. 
When used either singly or in combination they may 
preserve the keeping (quality of the milk for twenty- 
four to forty-eight hours. Salicylic acid is a more 
powerful preservative, but its bitter taste makes it 
unfit for use excej)t in very minute quantities. For- 
malin, which is a 40 per cent, solution of formaldehyde, 



140 HYGIEXE OF FOOD.> AXD FOOD SUPPLY 

is a powerful disiiifectaiit. Even very small quanti- 
ties can greatly euliance the keej)ing (jualities of milk. 
One j)art of fornuilin to .")(),()()() of milk, or about one 
teaspoonful to a forty-cjuart can of milk, will keep the 
milk sweet for from twenty-four to forty-eight hours. 
The objections to chemical j)reservation are the 
following: 

1. The chemicals referred to are even in minute 
(loses injurious to health. As they are injurious to 
adults, it is aj)parent that they must be even more 
harmful when ingested by delicate or sickly infants, 
for whose use most of the milk is intended. 

2. They change somewhat the digestibility of the 
milk. This is notably the case with formalin, which 
hardens the proteid matter. 

.3. A continuous and steady use of those chemicals 
will result in gastro-intestinal disturbances and intoxi- 
cation, especially in children. 

4. The use of chemicals, once permitted, even in 
minute doses, is bound to produce carelessness on the 
part of producers who will rely more upon the keeping 
qualities of the chemical than upon the cleanliness 
of production. 

5. As soon as chemical preservation of clean and 
good milk is allowed, it will be impossible to prevent 
the use of chemicals in the case of bad, old, and partly 
spoiled milk, and this increases the danger of the use 
of milk. 

The use of harmless preservatives has also been 
urged. Among these are peroxide of hydrogen, oxygen, 
and carbon dioxide. Peroxide of hydrogen is used 
in the amount of about two ounces to the forty- 



MILK INSPECTION AND TESTING 141 

quart milk can. It destroys most of the bacteria and 
at the same time disappears itself in the form of free 
oxygen. The use of hydrogen peroxide has not been 
tried extensively. The chemical is comparatively ex- 
pensive and its value as a preservative is problematic. 
Oxygen has been advocated as a disinfectant in milk; 
it is perfectly harmless and escapes after destroying 
the germs. The expense and the lack of proper appa- 
ratus have so far made this process impracticable. 
Carbon dioxide is said to destroy most germs in the 
milk when used under pressure of 75 pounds; the gas 
is harmless, does not change the character of the 
milk, and may be removed by aeration. This pro- 
cess is being exploited by a commercial concern, but 
its scientific and practical value still remains to be 
demonstrated. 



MILK INSPECTION AND TESTING. 

Methods of Examination and Testing. — The methods 
of examining and testing milk for the different impuri- 
ties it may contain, and detecting the adulterations 
to which it is often subjected, are physical, chemical, 
and bacteriological. 

Physical K.vatni nation. — By the physical examina- 
tion are determined the appearance, color, odor, and 
specific gravity of the milk, together with the varia- 
tions from the normal. 

Chemical K.r(nnin((t ion. —This determines the exact 
amount of solids in the milk, also the exact percentage 
of each solid in the fluid, 



142 HYGIENE OF FOODS AND FOOD SUPPLY 

Bacteriological E.vaminatio)i. — Tliis (kteriniues the 
number of bacteria in the milk and the presence or 
absence of |)atlio<]:enic bacteria. 

Precautions. The ])recauti()ns to be taken in the 
examination of milk are: (1) That the milk is thor- 
oughly mixed; (2) that it is not ])artly frozen; (.S) 
that the milk to be tested has not been j)artly churned 
or j)artly separated from its cream; (4) that it is not 
})artly or wholly' coagulated. 

in order to make proper tests, fair .s'aniplr.'i of the 
luill: nmst be taken from a ^iven quantity of the 
marketed milk, and precautions must be observed 
in the manner of takin*,^ samples, so as to obtain a 
fair and just sam])le of the whole quantity instead of 
only a small part of the fluid. For this a thorough 
mixing of the milk is necessary in order to give it 
uniformity. 

Partly frozen milk will not give a good test, because 
the frozen part represents the watery part of the milk, 
and the rest of the milk will show a richer fluid and a 
higher percentage of solids. 

]Milk which has been partly churned and has butter 
granules floating in it, or milk from which the cream 
has been wholly or partly separated, will naturally 
not give the normal percentage of fat in the fluid; 
thus the sample of the milk taken may not be a fair 
sample of the whole fluid. 

Milk which has been partly or w^holly coagulated 
will not give a fair sample for testing because of the 
separation of the whey and solids. 

Before samples are taken milk which is partly 
frozen must be thawed, so that the whole fluid be- 



MILK INSPECTION AND TESTING 143 

comes iniiforni; milk which has been partly churned 
and contains butter granules floating in it must be 
heated, so that these granules melt; milk which has 
been partly or wholly coagulated must be treated 
with alkalies sufficient to dissolve the coagulum; milk 
which has been partly separated from its cream must 
be thoroughly mixed and made uniform. In mixing 
milk care must be taken not to stir it too violently, 
so as to churn the milk or to mix it with air. The best 
means of mixing milk and of getting a uniform mixture 
is by pouring it from one vessel to another. 

Physical Examination. — The physical examination 
of milk is of very great importance, and may give 
valuable information to the inspector. The color of 
the milk, its opacity, its resistance to the immersion 
of a lactometer, its adherence to the instrument, the 
visibility of the instrument through the glass test- 
tube, are all valuable indications in the hands of an 
experienced inspector. Milk which is bluish in color, 
which allows the lactometer to sink wdth little resist- 
tance, which runs down the instrument in thin bluish 
streaks, which hardly adheres to the instrument, and 
which is so little opaque that the instrument is readily 
seen through the test-tube, is a milk which is poor 
in solids and which is ])robably either skimmed or 
watered, or both skimmed and watered. 

Cream Gauge. — Milk is often tested by the cream 
guage, pioscope, and lactoscope. The cream gauge 
is simply a graduated glass test-tube in which the 
milk to be tested is allowed to stand for twenty-four 
hours. At the end of this time the amount of the 
cream, as indicated in the yellowish layer on to]), is 



144 IIYC.IENE OF FOODS AND FOOD SUPPLY 

read ott". A good milk usually shows about 14 per 
cent, of cream. In order to facilitate the better separa- 
tion of the cream, the milk is mixed with an equal 
amount of water and the resulting layer of cream is 
multii)lied by 2 to show the actual amount of cream 
in the milk. The milk in the gauge should be put in 
a cold })lace, which favors the separation of the cream. 
This is a test upon whicli not much reliance can be 
placed. 

Ploscope. — The pioscope (Heeren) is a small in- 
genious instrument to test the quality of milk by its 
opacity and color. The instrument consists of a small 
rubber disk with a small depression in its center, and 
of a glass plate i)ainted in segments of varying shades 
of color, representing the color of cream, rich milk, 
normal milk, poor milk, skim milk, watered milk, 
etc. The inspector takes a drop of the milk to be 
tested and places it in the central depression of the 
hard-rubber disk, covers it with the glass plate, and 
compares the opacity and color of the milk with the 
various segments in the circle. In the hands of an 
experienced inspector this is a fairly trustworthy test. 

Lactoscope. — The lactoscope (P'eser) also tests the 
milk by opacity. The instrument consists of a grad- 
uated glass cylinder, in the center of which, at the 
bottom, is fixed a small white rod with several black 
lines on its face; 4 c.c. of the milk to be tested are 
put into the c^dinder, making the black lines on the 
rod invisible through the opacity of the milk. The 
test consists in carefully measuring the amount of 
water needed in the cylinder to render the fluid trans- 
parent, and to make the black lines upon the rod 



MILK INSPECTION AND TESTING 145 

visible. It is obvious that the poorer the quahty of 
the milk the less water will it be necessary to add to 
the cylinder in order to make the mixture transparent; 
and, on the contrary, it will be necessary to add more 
water the richer the milk. The instrument is grad- 
uated and shows the amount of estimated fat in the 
milk according to the number of the cubic centimeters 
of water added. 

Specific Gravity. — The testing of milk by its specific 
gravity is the test most frequently employed, and is 
very valuable in conjunction with the general physical 
examination of the milk. 

The specific gravity of milk depends on the solids 
in the fluid. Of these solids, sugar and the proteids 
are heavier than water, while the fat is lighter. The 
specific gravity of average normal milk is 1.029, and 
may vary in normal milk between 1.029 to 1.032. The 
specific gravity is calculated at 60° F. 

Milk which has been skimmed, i. e., from which a 
part or the whole of the cream has been separated, 
will show an increased specific gravity, because the 
absence of the fatty portion will make it denser and 
heavier. A milk which is diluted with water will show 
a decreased specific gravity because it is made thereby 
much less dense and thinner. 

Quevenne Lactometer. — The testing of milk with 
the Quevenne lactometer is based upon the relative 
six^ciflc gravity of the milk. This lactometer is grad- 
uated from 15 to 40, the scale reading as in ordinary 
hj'gronieters and showing the corresponding degree 
of specific gravity. A good milk (at 60° ¥.) will read 
32 upon this lactometer, showing a specific gravity 
10 



14G HYGIENE OF FOODS AND FOOD SUPPLY 

of 1.032, and average standard milk will read 29. A 
watered milk will read less than 29, aeeording to the 
amount of water (0 being water), while a skimmed 
milk will read more than 32 up to 40, according to the 
amount of cream subtracted. 

Lactouirfrr of the Ilcalfh Drjnirinicnt of New York. 
— This instrument, extensively used in many places 
in the Tnited States, is a larger instrument and is 
graduated 'differently from the Quevenne lactometer. 
According to this instrument it is assumed that 1.029 
is the lowest ])ermissible specific gravity for standard 
milk. Tlie 29 degrees are divided into 100 subdivi- 
sions from the top figure (showing the reading of 
water at ()0° F.) to 1()0, which corresponds to 29 on 
the Quevenne instrument, or to the specific gravity 
of 1.029 on the ordinary hygrometer. The lactometer 
is graduated from 1 to 120. According to the Board 
of Health lactometer a poor market milk will read 
100; a good rich milk will read between 100 and 110: 
a skimmed milk will read between 110 and 120; while 
a watered milk will read under 100, the amount of 
water added being indicated by the reading, i. e., 10 
per cent, of w^ater has been added if the lactometer 
reads 90°, 25 per cent, if 75°, etc. This instrument 
is the most convenient for use, as the stem is longer 
and the degrees may be read more readily, and also 
the exact amount of the probable addition of w^ater 
may be more readily calculated. 

As the lactometric readings are calculated at 60° 
F., corrections must be made for any difference in 
the temperature of the milk above or below 60° F. 
When the difference in the temperature is very great it 



MILK INSPECTION AND TESTING 147 

is best to reduce or increase its temperature to within 
10° of ()0°. The correction for the temperature is the 
0.1 degree of the Quevenne lactometer for every 
degree of temperature, and 0.3 degree of the Board 
of Health lactometer for every degree of temperature 
above or below 60°; added to the reading when the 
temperature of the milk is above 60° F., and sub- 
tracted from the reading when the temperature of 
the milk is below 60° F. The usual rough correction 
for the Board of Health lactometer is 4° on the lac- 
tometer for every 10° on the thermometer, added or 
subtracted, according as it is above or below 60° F. 

As the specific gravity of milk is increased by skim- 
ming and decreased by watering, some milk dealers 
first subtract a certain amount of cream, thus in- 
creasing the specific gravity and lactometer reading, 
and then add sufficient water again to decrease the 
specific gravity and lactometer reading to about 
normal, so as to deceive the inspector and give an 
adulterated milk a normal reading on the instru- 
ments. The only recourse of the inspector is then 
to compare the physical appearance of the sample 
of milk with normal milk, when there will appear the 
dift'erence in the color, opacity, and density of the fluid. 

Chemical Examination.^ — The chemical tests of milk 
consist in the examination to discover the exact per- 
centage of solids, and the amounts and percentage of 
each component solid. The usual tests are those of 
weighing and evaporation for the exact amount of 
solids, and the Babcock test for the determination 
of the amount of fat in the milk. For the complete 
chemical and bacteriological tests^of milk the student 
is referred to special works on* the subject. 



CHAPTER IV. 

THE HYCHENE OF SCHOOLS AND OF SCHOOL 
CHILDREN. 

THE SCHOOL CHILD. 

By c()inj)uls()ry education the State forces children 
between the a^es of six and twelve or fourteen to 
be sent to, and to he kept in, school for the greater 
part of the day during six or eight years. These 
years are the most important in life. They represent 
a period of formation, growth, and development. 
Having compelled the child to remain in school dur- 
ing the most important period, it is the duty of the 
State to take care not only of the mental growth and 
development of the child, but also of its moral and 
physical condition and development. 

Not long ago it was deemed sufficient for the State 
to provide means and teachers for the cramming of 
the child's intellect w^ith rudimentary know^ledge of the 
elementary sciences. At present, broader ideas pre- 
vail. The child is the greatest asset of the State. 
The child's mental and moral development and growth 
go hand in hand wdth its physical growth and develop- 
ment. The school influences not only the child's 
mental growth, but profoundly affects its physical 
well-being. No care of the school child is therefore 
complete that does not take into consideration the 
physical condition and the bodily growth of the child 



SCHOOL CHILD 149 

as well as the prevention of the evil influences of school 
life upon its health. 

What are the influences of school and school life 
on the physical well-being of the child ? 

These influences may be grouped as follows: 

1. The influence of the school and the school room. 

2. The influence of the age and growth of the child. 

3. The influence of the methods of teaching and of 
the mental training given. 

4. The influence of the herding together of a large 
number of children. 

The Influence of the School and School Room. — No per- 
son of tender age may remain for six or seven hours 
a day during six to eight years in a place without 
being profoundly influenced by the condition of the 
place. The hygiene of schools begins, therefore, in 
the proper construction and care of school houses and 
school rooms. 

The Influence of Age and Growth of the Child. — The 
child when it enters school at the age of six years 
weighs on the average forty-three to forty-five pounds, 
and its average height is forty-three to forty-four 
inches. When the child leaves school at fourteen 
years of age its average weight is one hundred pounds 
and its average height five feet. During this period 
the physical being of the child undergoes remarkable 
transformation; it is extremely sensitive to external 
influences, and its health must be carefully nurtured 
and promoted. It is imperative, therefore, to strictly 
supervise the personal hygiene of the child, its nutrition, 
clothing, dentition, physical development, etc. Mother 
and school are bound to take care not onlv of the 



150 HYGIENE OF SCHOOLS AND OF CHILDREN 

child's unripe mind, ])ut also of its unripe and ij:r()wing 
})ody. This is aceoniplished by physical examinations 
of the child on its entering]; school, by supervision of, 
and j)rovisi()n for, its proper feeding, by the guiding 
of its muscular exercises, by ])rovi(ling baths, play- 
grounds, etc. 

The eyes of the children need Acry careful atten- 
tion. The light of school rooms, as well as the distance 
of the desks from the slate-boards, etc., must be 
properly adjusted, so that no harmful effects to the 
eyes ensue. 

One of the diseases which are so frequently among 
school children is my()})ia. It is a disease directly 
due to school life, to study, to defective light and 
illumination, to improper positions, faulty seats and 
desks, defective methods of writing, too small print, 
and too much eye-strain generally. Children who 
come to school with some degree of weak vision 
gradually develop more pronounced near-sightedness, 
which increases in each grade of school. Thus in one 
New York school the percentage of myopics in lower 
grade 8 was 8 while in the higher grades it w^as 20.2. 

The teeth of the children very often are effected by 
various defects and diseases, and these lead to certain 
malformations of the mouth, improper breathing, 
improper mastication, and improper development. 
With the ignorance prevailing among many classes 
of the population, it is impossible to depend upon the 
parents for the proper care and treatment of the 
irregularities of dentition, and the school through its 
dental surgeons should take care of this important 
field of hygiene. 



SCHOOL CHILD 151 

There are certain diseases of the bone, rickets, 
deformities of the spine, etc. The latter especially 
are due to improper positions in school and may be 
prevented by taking proper care of the children within 
the school, by the adjustment of seats and desks, 
and by strict supervision on the part of the teachers 
of the positions and attitudes of the children during 
school work. 

One of the most important defects among a large 
class of children is malnutrition. This is often due 
not so much to the lack of sufficient food as to the 
ingestion of improper food. Recent investigations 
have also shown that a great many children come to 
school breakfastless, and that many of them content 
themselves with but a very slight lunch, often con- 
sisting of ingredients insufficient for nutrition and 
improper for digestion. It is absurd to endeavor to 
teach the child and to train its mind while its body 
suffers from lack of nourishment. A healthy mind 
can exist only in a healthy body. It is the duty, 
therefore, of the school to provide for the proper feed- 
ing of the school children during school hours. This 
feeding should be given at a nominal cost to those who 
can afford it, and without any cost whatever to those 
children whose parents cannot afford the expense. 

Influence of Teaching and Mental Training. — The 
methods of teaching and the subjects taught have 
an important influence, not only upon the mind, but 
also upon the body of the child. The unscientific 
and irrational methods of teaching as yet prevailing 
in many schools do much harm to the mind, inju- 
riously infiuence the nervous system of the child, and 



ir)2 HYGIENE OF SCHOOLS AXD OF CHILDREN 

do liarni to tlie pliysical condition of the body. The 
preparation of a child for useful future citizenship 
does not mean the stuffing; of his mind with useless 
hook knowledge, to he forgotten as soon as he is out 
of school. The methods of teaching should he rather 
a training of the growing brain and mind, to gather 
for itself useful facts and to garner knowledge for its 
own use. The old hot-house methods of child cul- 
ture are rapidly giving way to new natural methods of 
mental training. 

Especially harmful to the child's nerves and physique 
are the present systems of competitive examinations, 
and the o})solete methods of punishment, etc. 

The Influence of Crowding a Large Number of Children 
in the Schools. This is tlie greatest evil of school life 
and the greatest danger to the health and lives of 
school children. A child in school comes in close bodily 
contact with other children, with a consequent possi- 
})ility and probability of catching and spreading infec- 
tious diseases. The infectious diseases of school life 
may be grouped as f ollow s : 

Diseases of the Eye. — Conjunctivitis, blepharitis, 
pink-eye, granular conjunctivitis, or trachoma. 

Diseases of the Skin. — Pediculosis, ringworm, scabies, 
impetigo, favus, molluscum contagiosum. 

General Infectious Diseases. — Rotheln, measles, scar- 
let fever, diphtheria, typhoid, mumps, w^hooping-cough 
chicken-pox, etc. 

The diagnosis of the various infectious diseases is 
wdthin the province of the medical inspectors of 
schools. The exclusion of the children is made under 
the recommendation and order of these physicians. 



SrifOOL HVILDIKG 153 

The school nurses should have, and usually do have, 
tieneral knowledge of the initial symptoms of the 
various infectious diseases. This medical instruction 
is given to the nurses in their medical curriculum, and 
may therefore be omitted here. 

THE SCHOOL BUILDING. 

The school is a place where children of tender age 
remain daily for long hours. The physical, mental, 
and moral conditions of the children during their 
school life is partly influenced by their sojourn in the 
school building. The preservation, therefore, of the 
health of the children demands that the school building 
be constructed and maintained in the best sanitary 
condition. 

The sanitation of the school building should begin 
before its construction. The site for the school build- 
ing should be selected from among the best in the town 
or city. The soil should be dry, porous, well-drained. 
The location should be distant from fa^ctories, mar- 
kets, boiler shops, saloons, elevated railroads, and 
other establishments which for one or more reasons 
may become offensive and be a nuisance to the school. 
It is advisable to surround the school building with 
playgrounds and, if possible, with a public park. 

There should be very little economy practised in the 
purchase of the site for the school building and in the 
construction of the building itself. Except in very 
small localities no school building should be of frame 
construction. Brick, stone, or reinforced concrete 
should be used. 



154 UYGIEXE OF SCHOOLS; AXD OF CHILDREN 

TJie scliool building should he hniitod in lieight and 
should not contain more than four or five stories, 
preferably fewer. The school building should be 
constructed of fireproof materials and its inner trim- 
ming should be made fireproof. 

The cellar and the lowest story should be dry, well 
lighted and ventilated. They may be used for the 
location of boilers, machinery, etc., but should not be 
used for workshops, gymnasia, or any other similar 
purposes. 

There should be j)lenty of entrance and exit doors 
at fre(juent intervals. These should be broad, light, 
iind fireproof, and should be sufficient to empty the 
building within a very short time in case of fire or panic. 

The size of school buildings is best limited. It is 
better to construct three buildings for two thousand 
children each than one building to accommodate six 
thousand children. 

The walls, floors, and ceilings should be soundproof 
and also proof against dust, damp, and vermin. 

Some buildings demand a minimum of thirty square 
feet of floor space for each child. 

The surfaces of walls and ceilings within the school 
should be smooth so that dust cannot adhere to them, 
should be easily washable, and painted with bright 
tints. 

The subdivision of the school house into school 
rooms should be made by solid partitions if possible, 
reserving one floor w^ith movable partitions for general 
assembly rooms, etc. The rooms should not be less 
than thirteen feet in height. The usual size of a school 
room is thirty by twentyrfive feet. 



SCHOOL BVILDISG 155 

Lighting. — The window area of school houses should 
not he less than one-fourth of the floor space. The 
top of the windows should be as near the ceiling as 
possible and should reach to about four feet from the 
floor. The best white glass, or preferably plate, should 
be used for the panes. Excessive glare should be con- 
trolled by appropriate shades from the top and the 
bottom of the windows. Electric lights should be 
used for artificial illumination. 

Ventilation and Heating. — There has been much 
controversy as to the proper methods of ventilation 
for school buildings. There is no doubt whatever 
that school buildings, with the large number of chil- 
dren in the school rooms, cannot be ventilated properly 
by natural means, or by means of windows or open- 
ings in the windows, walls, or ceilings. There cannot 
be too much fresh air introduced into the school rooms. 
Provision should be made for artificial mechanical 
ventilation in all school buildings. 

The installation of a proper mechanical ventilating 
plant is an engineering problem, the solution of which 
should be given only to most competent persons. 
The combined plenum and vacuum systems are the 
best for school ventilation. By this method the foul 
air from the room is exhausted through outlet open- 
ings in the school room, and the fresh air is introduced 
into the room through inlet openings in the same. 

The advantage of this system of ventilation is that 
it may be combined with a system for heating and 
cooling the air which is introduced into the room. 
In the winter the air introduced through the tubes 
may be warmed by passing over steam coils, while 



loC) IIVaiESE OF SCHOOLS AXD OF CHILDREN 

in suininer the air may \)v conlcd by passing through 
a cold chamber. 

Even in very small school buildings no local heating 
should be used. A hot-water heating plant may be 
cheaj)ly installed even in small buildings. The com- 
bined heating and \(Mitilating system must also make 
j)rovisi()n for i)r()per regulation of temperature by 
thermostats. 

Water Supply. — An ample supply of pure water 
should be liad in e\'ery school room and there should 
be no need for the pupils to go long distances to obtain 
a drink. Sanitary drinking fountains are the best and 
all couHuon ('Ui)s should be prohibited. The filtering 
plant for the water supply of the school should be 
installed in a central location where it can be watched 
and kept clean. 

There should be toilet accommodations of the best 
type on every floor of the building. The water closets 
should be provided with automatic flush so as to be 
self-cleansible. 

Provision should be made for wash rooms, shower 
baths, swimming tanks, etc. 

Cleaning. — The utmost care should be taken to keep 
all surfaces in the school room clean, and a routine 
daily, weekly, and periodical cleaning system should 
be adhered to. The obsolete method of cleaning by 
the feather duster or dry rag should be abolished. 
Whenever possible, vacuum systems should be in- 
stalled in every school room. The school funiture 
and other surfaces should be cleaned daily with damp 
clean rags. 



CARE OF THE CHILD I\ SCHOOL 157 

School Furniture. — The desks, seats, platforms, and 
blackboards should be properly constructed, and the 
desks and seats of the pupils should be made so as 
to be adjustable to the size of each child in order to 
prevent it from assuming improper attitudes while 
at work. The depth of the school room should not 
be too great and the distance of the rearmost pupil 
from the platform should not exceed twenty feet. 
It is best not to have the seats and desks attached 
to the floor, but to make them movable. 

Some improved substitute is needed for the dust- 
creating chalk used on slate blackboards. 

The Supervision of School Cleaning and Sanitation. — 
The common method of leaving all questions in regard 
to the care of the school building, rooms, and furniture 
to the janitor is entirely wrong. Each school should 
be supervised in its care and cleanliness by a trained 
school nurse who should have the supervision over 
janitors and cleaners, and whose duty it should be to 
make daily and hourly inspection of all parts of the 
school and to see that each part is properly cleaned 
and taken care of. 

The appointment of such a supervising school nurse 
for the cleaning and sanitation of the school building 
would be of great benefit to the sanitation of the 
school and would greatly improve the health of the 
school children. 

THE CARE OF THE CHILD IN SCHOOL. 

The purpose of keepnig the child hi school from the 
age of six to foiu'teen and more is not only to give the 



158 HYGIENE OF SCHOOLS AND OF CHILDREN 

cliild a mental training and education for use in its 
adult life, hut also to promote the physical develop- 
ment and growth of the child into a healthy and useful 
citizen, ca])al)le of holding his own in the struggle for 
existence. 

The mental and moral training of the child is given 
into the hands of teachers and principals, whose duty 
it is to devise and institute a proper system of intel- 
lectual activity and education and to give to the child 
the foundations of knowledge as well as a moral train- 
ing. The various systems of teaching and of mental 
training, the selection of the courses, and of the 
teachers to guide th^ mental and moral training of 
the child, are in the pro\'ince of mental hygiene and 
of the science of pedagogy. 

The school has also a certain influence upon the 
health and life of the child and is the place where very 
often certain infectious diseases are communicated 
from child to child. A duty of the school authorities, 
therefore, is to prevent as much as possible the spread 
of these diseases. 

These functions — the care of the health of the 
school child, the promotion of its normal growth and 
development, the prevention of general, and especially 
of contagious, diseases — are recognized as included in 
the hygiene of schools and have been intrusted to the 
school physician and to the school nurse. 

FUNCTIONS AND DUTIES OF NURSES IN 
SCHOOLS. 

Medical school inspection cannot be efficiently 
accomplished without the assistance and aid of the 



DUTIES OF SCHOOL NURSES 159 

school nurse. She is an inij)ortant and integral part 
of medical school inspection. Her special functions 
and duties in the school may be summed up as follows : 

1. General and special assistance to the medical 
school inspector. 

2. Preliminary inspection of children: 

(a) For detection of physical defects. 
{b) For detection of contagious diseases. 

3. Visits to homes of children to investigate causes 
of absence from school. 

4. Advice to children and their mothers on correction 
of defects and improvement of health. 

5. First aid and emergency treatment. 

6. Treatment of children for certain physical defects 
and contagious diseases. 

General and Special Aid and Assistance to the Medical 
School Inspector. — With the present organization of 
medical school inspection and the small number of 
physicians assigned to this work in schools, it is abso- 
lutely impossible for the physicians to do good work 
or even to hope to efficiently accomplish the manifold 
purposes of medical school inspection. It is obvious 
that one physician assigned, as he often is, to three 
schools, with an attendance of from five to ten thousand 
children, cannot do more than routine perfunctory 
work. Even if there were assigned to each school 
three full-time physicians, the enormous amount of work 
coul(l not be accomplished without the active aid and 
})arti('ipati()n of trained scliool inn*ses. There is there- 
fore gn^at uvvaI for the appointment of many additional 
trained nurses for our schools. Indeed, it is claimed 
by competent school authorities that there should be 



IGO IIYGIEXE OF SCHOOLS AND OF CHILDREN 

assijxned in each school at least one nurse to every two 
hundred or two hundred and fifty pupils. 

Inspection for Detection of Physical Defects and Deten- 
tion of Cases of Contagious Diseases. A school nurse 
should l)c familiar with the hci<;lit and wei<^ht charts of 
children and should he ahle to detect })hysical defects 
common to children. She should also be familiar with 
the symj)toins of various conta<?i()us diseases with a 
view of their early detention and, at least, detention 
of those children who j)resent suspicious symptoms for 
a more thorough diagnosis hy the ])hysician. 

PhijsicaJ Defects. — The physical defects common to 
children in school are the following: 

Defective vision. 

Defective hearing. 

Defective nasal breathing. 

Hypertrophied tonsils. 

Tuberculous lymph nodes. 

Defective teeth. 

^Malnutrition. 

Chorea. 

Orthopedic defects. 
The more serious cardiac and pulmonary defects 
will be detected by the physician on his thorough 
examination of the child. 

Defective vision and hearing may be detected by the 
application of simple tests. 

Defective nasal breathing and hypertrophied tonsils 
may easily be detected by inspection and examination 
of nose and throat. 

Tuberculous lymph nodes are detected by inspection 
and palpation. 



DUTIES OF SCHOOL NURSES 1()1 

Defective teeth aiied nuiluutrition are detected by 
inspection, as are also orthopedic defects and more 
advanced cases of chorea. 

Contagious Diseases. — The nurse on visiting each 
school should inspect the room which is assigned for 
the purpose of inspecting the children. The following 
contagious diseases are to be looked for. 

Eye Diseases. — Acute conjunctivitis, pink-eye, tra- 
choma, etc. 

Skin Diseases. — Pediculosis, ringworm, scabies, favus, 
impetigo, molluscum, contagiosum. 

General Diseases. — Slumps, chicken-pox, whooping- 
cough, German measles, measles, diphtheria, scarlet 
fever, smallpox, tuberculosis. 

Exclvsion of Children for Contagions Diseases. — 
erases of acute conjunctivitis, trachoma cases, certain 
skin diseases and pediculosis, without live pediculi, 
may be allowed to attend school while under treatment, 
either by a private physician, a dispensary or the school 
nurse. Contagious skin diseases with extensive lesions, 
pediculosis with live pediculi, and all general contagious 
diseases are excluded from school attendance. 

Home Visits by Nurse. — The nurse must exercise 
great tact in her visits to the homes of children who are 
absent from school. The purpose of such visits is to 
discover the cause of absence and the possible ])resence 
of contagious diseases and attendance at school of some 
nienibcrs of the family. The nurse should not })lay the 
role of detective but rather that of family adviser and 
counselor. (Iiildren are often kept home for slight 
manifestations of illness which the nurse may recognize 
as symptoms of contagious disease. She should then 

n 



1G2 HYGIENE OF SCHOOLS AND OF CHILDREN 

advise the calling: in of a competent family physician. 
In case of susj)icions throat symptoms cultnres may be 
taken hy the nurse for bacteriological diagnosis. 
Reports must be made to the medical school authorities 
of the work and findings of the school nurse at the home 
of the patient. 

Emergency and First-aid Treatment.— In the absence 
of the school })hysi('ian all emergency cases are treated 
by the nurse in the school, whenever other treatment 
is not available. Slight or more severe injuries, cuts, 
results of falls, and other accidents occurring to 
school children in the school building should be 
promi)tly treated by the school nurse. It would be 
well if every school would provide a first-aid and emer- 
gency treatment room with the proper and necessary 
equipment and appliances. Children should be in- 
instructed to apply to the school nurse for the appli- 
cation of tincture of iodine for every slight scratch or 
cut in order to prevent possible septic infection. 

Advice as to Physical Defects. — Defects of the Mouth 
and Teeth. — (a) If the child's teeth are decayed it 
should be taken to a dentist at once. 

{h) The teeth should be brushed after every meal, 
using a tooth brush and tooth powder. The following 
tooth powder is recommended: 

2 ounces precipitated chalk. 
^ ounce powdered castile soap. 
1 dram powdered orris root. 
Mix thoroughly. 

This prescription can be filled by any druggist at a 
cost not to exceed fifteen cents. The child should take 



DUTIES OF SCHOOL NURSES 163 

the tooth brush and powder to the school and receive 
instructions from the nurse as to their proper use. 

Defective Vision and Hearing. — Proper advice should 
be given to the children if defects in hearing and vision 
are discovered. A more thorough examination should 
be made by the physician with the view of prescribing 
exact treatment for remedying the defects. Errors of 
r.efraction should be corrected by properly fitted glasses. 
Special attention should be paid to any discharges 
from the ears as these may be symptoms of serious 
and contagious diseases. 

Malnutrition. — Proper advice and counsel should be 
given to the child in case of manifect malnutrition. 
Correction of the dietary and advice to mothers as to 
proper feeding may be in the province of the school 
nurse. Anemia and malnutrition, when extreme, 
should be taken in hand by the physician and the child 
referred to special open-air classes and other methods 
employed for the cure of these conditions. 

Treatment by Nurse of Certain Contagious Diseases. — 
Pediculosis. — A child affected with live vermin of the 
head or body should be excluded from school. The 
best treatment for the destruction of body lice is the 
boiling of the underwear of the child and fumigation 
of the clothing. The bathing of the child and instruc- 
tion in cleanliness should follow the preliminary treat- 
ment. 

Hair and Scalp Lice. — The best treatment for this 
affection is that with kerosene oil. I\Iix one-half pint 
of sweet oil and one-half pint of kerosene oil. Shake 
the mixture well and saturate the hair with the mixture. 
'J'hcn wrap the head in a large bath towel or rubber 



104 HYGIENE OF SCHOOLS AXD OF CHILDREN 

cap so that the head is entirely covered; the head 
must remain covered from six to eight hours. 

After removing the towel the head should he sham- 
pooed as follows: To two quarts of warm water add 
one teaspoonful of sodium carhonate. Wet the hair 
with this solution and then a])ply castile soap and rub 
the head thoroughly about ten minutes. Wash the 
soap out of the hair with re])eate(l washing of clear 
warm water. Dry the hair thoroughly. 

Nits. — If the head is shampooed regularly each week 
as above described, it will cure and prevent the condi- 
tion of nits. Common vinegar added to the sham- 
pooing mixture will greatly assist in separating the nits 
from the hair. 

Methods of Treatment Employed by the School Nurse 
in Contagious Eye and Skin Diseases. — Favus. — Ri7ig- 
worm of Scalp. — Mild cases: Scrub with tincture of 
green soap and cover with flexible collodion. Severe 
cases: Scrub with tincture of green soap, paint with 
tincture of iodine and cover with flexible collodion. 

Ringworm of Face and Body. — Wash with tincture 
of green soap and cover w^ith flexible collodion. 

Scabies. — W'ash with tincture of green soap and apply 
sulphur ointment. 

Impetigo. — Remove crusts with tincture of green soap 
and apply white precipitate ointment (ammon. hydrag.). 

Mollnscum Contagiosum. — Express contents: Apply 
tincture of iodine on cotton-covered toothpick. 

Conjunctivitis. — Irrigate with solution of boric acid. 

Trachoma. — ^Trachoma is not treated by the nurse. 
Children so affected are instructed as to the necessity 
for treatment, as per following instructions: 



DUTIES OF SCHOOL NURSES 105 

Instructions to Parents Regarding Trachoma. — Tra- 
choma is a contagious disease of the eyehds. If left 
untreated it is very dangerous to the eyesight. 

It first attacks the inner surface of the eyeUd, later 
it spreads to the eyeball itself and causes loss of sight. 

In the beginning the eyes may be red and watery, 
and they may, from time to time, contain matter, but 
often for a long time there are no symptoms that the 
person notices, and the disease is frequently first dis- 
covered by the doctor. It is very difficult to cure 
trachoma, and it is the more difficult the longer the 
disease has lasted. For this reason trachoma should 
be detected as early as possible. It is contagious 
when secretion, that is to say "matter," is present. 
This secretion is for the most part conveyed by means 
of towels, wash-cloths, and handkerchiefs, and persons 
with trachoma should always be careful that their 
towels, wash-cloths and handkerchiefs are used by 
themselves. It is therefore not on the street that 
trachoma is transmitted from one person to another, 
but most generally in the home, and it is therefore 
in the home that the greatest precautions should be 
taken. 

Children who suffer from trachoma are not allowed 
to attend school unless they are regularly treated. 



CHAPTER V. 
TIIK IIYCIF.XE OF OCTrPATTONS. 

OCCUPATION AND HEALTH. 

The functional activity of organs in the normal 
way is a physiological condition of health; the disuse, 
more or less prolonged, of any organ is, as a rule, 
followed by atrophic changes. While the normal pur- 
suit of occupation is therefore a condition of health, 
pursuit of most occupations in the present industrial 
system is often followed by certain pathological 
dianges in the human body. 

It is certain that the health of workers is profoundly 
influenced by the kind of occupation they pursue, and 
that their very length of life is determined by their 
particular occupation. Occupation is a potent factor 
in the determination of human longevity. If the period 
of infancy and childhood and the hours devoted to 
sleep are deducted from man's life the greatest part 
of it is spent in industrial activity and is necessarily 
largely influenced by the occupation engaged in. 

The relative number of those who die w^hile in pur- 
suit of their occupations bears an important relation 
to the healthfulness of the occupations. Mortality 
statistics clearly prove this contention. When the 
mortality of members of various trades is compared, 
a great difference in the rate of death per thousand 



OCCUPATION AND HEALTH 167 

is found. This difference frequently embraces long 
periods, large numbers, and many different countries, 
showing a uniformity in the increase of mortality-rates 
of the members of one trade over the mortality-rate 
of members of another trade. 

It is shown, for instance, according to Ogle's tables 
from the experience of Great Britain, that clergymen 
have the lowest death-rate, next to them gardeners 
and farmers, while members of trades like bakers, 
tailors, liquor dealers, file-makers, and others suffer 
from a much higher mortality-rate. The mortality- 
rate of clergymen is therefore put as 100 in the follow- 
ing table as a basis for comparison : 



Mortality- 
Occupation, rate. 

Clergymen 100 

Gardeners 108 

Farmers 114 

Bakers 172 

Tailors 189 

Glass-workers 214 

Liquor dealers 274 

File-makers 300 



The United States mortality tables also show that 
the mortality-rate per thousand of engineers and 
surveyors was 8.2; tailors, 11.8; printers, 12.1; car- 
penters, 17.2; cigar- and tobacco-workers, 18.7, and 
millers, 26.6. 

Thus it is found that the mortality-rate of members 
of one trade is much higher than the rate for workers 
in another trade, and if the causes of the increased 
mortality are sought for, it is usually found that there 
are some specific dangers in the occupation whidi 
shows the highest rate of mortality. 



lOS HYGIENE OF OCCrPATIONS 

Morbidity. — Not only tlie ItMitj^th of life of the work- 
ers is determined by their ocenj)ati()n, hnt also their 
state of health during life. If a physieal examination 
of tlie workers in one trade is made, and the results 
are compared with those of a similar physical exami- 
nation in another trade, a difference in the morbidity- 
rate, according to certain factors existing in eacli 
occupation, is usually found. 

The experience of ^a^i()us sick benefit insurance 
societies in (icrmany, Austria, and other continental 
countries in wliich state insurance exists, shows a 
great difference in the rate of disease among the 
workers in different occupations. A recent medical 
examination undertaken by the New York State 
Factory Investigating Commission of 2283 persons, 
in the tailors', bakers', tobacco, and furriers' trades, 
has shown a large percentage of members of these 
trades suffering from one or more diseases. 

Tuberculosis. — The most frequent disease in indus- 
trial life from which the members of various trades 
suffer is tuberculosis. Indeed, tuberculosis has been 
named an industrial disease. All statistics confirm 
this statement. They show that tuberculosis as a 
cause of mortality in active w^orkers between the 
ages of twenty-five and forty-four is responsible for 
from one-third to one-half of all the deaths. Accord- 
ing to statistics of the Prudential Insurance Company 
of America presented at the International Congress of 
Hygiene and Demography in 1912, tuberculosis was 
show^n to be the cause of death of 35.5 per cent, of all 
occupied males between the ages of fifteen and twenty- 
four. Among farmers the rate at the same age was 33.1 ; 



OCCUPATIOX AM) HEALTH 109 

among clerks, 4,"). 9 j)er cent; among glass-workers, 
48.1 per cent.; among stone-workers, 47.S per cent.; 
among plnmhers, 42.1 per cent.; among printers, 49.5 
per cent.; cigar-makers, 45.5 per cent.; tailors, 48.6 
per cent.; textile-workers, 47.5 per cent. 

Hoffman has also shown the great mortality among 
workers in dnsty trades. According to Somerfeld, the 
mortality of Berlin workers in non-dusty trades was 
2.39 per 1000, while in dnsty occupations it was 5.42 
per 1000. 

Diseases of Occupation. — There are a number of 
diseases which are peculiar to certain occupations, and 
they have been therefore called industrial diseases. 
Among these diseases besides tuberculosis, which has 
been already referred to, the following are the most 
important : 

1. Respiratory Diseases. — The term pneumonokoni- 
osis is applied to an affection of the lungs due to the 
deposit of dust among its cells. ^Miners, charcoal 
drivers, metal and glass polishers, stone-masons and 
plasterers, and other workers in especially dusty 
trades are apt to have the dust lodge in their lungs, 
where it causes a special fibroid disease which even- 
tually is followed by an infection with tubercle bacilli 
and frequently leads to death. Pneumonia, bronchitis, 
and emphysema are also frequently found among 
workers. They are due to exposure, difference in 
temperatures, and other factors in the occupation. 

2. Nervous Diseases. —Among the nervous diseases 
which are frequently found among workers are those 
due to overstrain, tension, extremes of heat, shocks, 
and other untoward occupational factors. There are 



170 IIYGIEKE OF OCCUPATIONS 

also certain iutvous diseases due to the overstrain of 
particular organs; the most common of these are 
writer's cramj), telegrapher's spasm, etc. 

3. Diseases of the Eye. — Among the j)rincipal eye 
diseases are eye-strain, nystagmus, and other affec- 
tions due to excessive light, heat, overuse, overstrain, 
and accidents. 

4. Ififecflous Diseases. — A number of infectious dis- 
eases are due to infection hy materials which are 
handled hy the workers. The most imj)ortant of these 
are anthrax, which is often found among workers 
with hides and cattle, ankylostomiasis, and others. 

5. Other Diseases. — There are also a number of 
diseases of the digestive tract, of the skin, and of 
other organs, due to the various factors in various 
occupations. 

Summary. — The effects of industries on health may 
be summed up as follows: 

1. Sudden death due to accidents, falls, burns, 
explosions, etc. 

2. Total or partial disability from the same causes. 

3. Sudden deaths from acute intoxications by 
poisons, fumes, and gases. 

4. Deaths from chronic intoxications by the same 
elements. 

5. Deaths due to infectious material in industries. 

6. Diseases due to direct action of dangerous ele- 
ments in trades. 

7. Diseases due indirectly to industries and occu- 
pations. 



INDUSTRIAL FACTORS INFLUENCING HEALTH 



INDUSTRIAL FACTORS INFLUENCING HEALTH. 

There are a number of factors in industry and 
various occupations which influence the health and 
bring about occupational diseases and the comparative 
shortening of the lives of industrial workers. They 
may be grouped as follows: 

1. Personal factors. 

2. Work place. 

3. Working conditions. 

4. Specific occupational dangers. 

Personal Factors. — The personal character of the 
worker, his fitness for the occupation which he selects, 
his industrial training, his capital of bodily health 
and mental training, his vital resistance, his age 
and sex, all are important factors determining the 
influence of the work upon the w^orker. 

The greater the sum of health with which the 
worker starts out at the beginning of his career the 
more efficient will be his work, and the less likely will 
it be that he will suffer from the adverse conditions 
incident to his work. His susceptibility and vital 
resistance depend partly on his physical health and 
partly on individual idiosyncrasies. There are, for 
instance, those who are less susceptible to certain 
poisons than others, enjoying a certain immunity 
against the eft'ect of infections and poisons to which 
others (|ui('kly succumb. 

The j)r()per selection of a trade according to fitness 
is very important. A feeble individual selecting a 
trade which requires strenuous physical exertion will 



172 HYGIEXE OF OCCrPATIONS 

succuinl) sooner to the effeets of the trade than a 
r()l)nst worker. 

Age. — The a«;e at which work is begun is also of 
threat iniportjinee. 'J'liere are nearly 2,()()(),()()0 chil- 
dren under the age of sixteen enii)l()yed in the various 
occupations in the United States. That the developed 
organism is miable to withstand the strains of con- 
tinuous and prolonged muscular or other exertion is 
(>1)\ ious. The mind and body of a child under sixteen 
should l)e carefully nurtured and not allowed to be 
subject to physical or mental strain for long periods. 
In normal society there should be no economic cause 
tor parents of children under sixteen to need the 
wages of the child workers or to impose the burden 
of economic independence upon the physically unripe 
child. The efiects of labor on children may be summed 
up as follows: 

1. Injury to the weaker organism. 

2. Interference with their growth and physical 
development. 

3. The production of special and other bone deform- 
ities. 

4. The low^ering of vital resistance and the predis- 
posing of the body to disease. 

5. The stunting of mental and moral development. 

6. The physical, moral, and mental degeneration. 

7. The shortening of life. 

The Labor of Women. — Under the present economic 
conditions a large number of women are employed 
in gainful occupations, and form a very important 
part of the industrial population. There is hardly a 
trade or industry in w^hich women do not participate. 



The question what effect, if any, occupation has 
upon women has been studied by many investigators, 
and certain conchisions have been reached which are 
at present universally accepted. These conclusions 
regarding women's labor may be summed up as follows: 

1. That there are certain forms of labor, especially 
those requiring great physical exertion, which should 
not be followed by women because of their compara- 
tive physical weakness. 

2. That women cannot bear with impimity as long 
hours of labor as men; that therefore the hours of 
labor should be shortened, and should not exceed 
eight per day. 

3. That there are certain periods each month during 
w^hich women should not be allowed to work at all, 
because they are in a semipathological state. 

4. That women who bear the burden of pregnancy 
and childbirth should not be allowed to work during 
these periods. 

5. That night work is injurious to the health of 
women. 

6. That those women who are burdened with the 
care of children or of a household should not be ex- 
pected to participate in industries to the same extent 
as those who are free from these burdens. 

7. That owing to the greater susceptibility of women 
to certain industrial poisons, they should be excluded 
from work m all industries in which these poisons are 
I)r()(lu(r(l. 

The Work Place.— The i)la('e where the work is car- 
ried on has a great influence upon the health of the 
worker. The eHVct of the factory or workshop upon 



174 IIYGIEXE OF OCCUPATIONS 

the licalth of the worker depends upon its proper 
construction, upon the fire protection, the provision 
for Htjht and ilhimination, adequate ventilation, ])roper 
lieating, tlie drainage, ])hnnl)inp:, and general sanita- 
tion of the j)Iace. 

At present nuicli work is done at lionie, especially 
by women and children. The injurious effects of 
"honi(* work" or "sweat-shoj) work" are due partly 
to the unsanitary conditions under which the home- 
workers arc compelled to work, and partly to other 
causes, such as the tendency in home work for small 
children to participate, the longer periods of the work 
at home, the danger that the home will be infected 
by the dust and manufactured materials brought 
into it, or that the materials will carry infection from 
the home. A great many of the factory buildings are 
entirely unsuited to the purpose of manufacture and 
are unfit for the workers. The existence of so many 
unfit factories is a cause of a great many of the evils 
of modern factory system. The dangers from fire in 
factories and workshops, as they are ordinarily con- 
structed, are very great. These dangers are due to: 

1. The congestion of factories in certain areas. 

2. The toogreat heightof many buildings inlarge cities. 

3. Faulty internal construction. 

4. Bad internal arrangements. 

5. Too many workers on each floor. 

6. Insufficient exits. 

7. Improper exits. 

8. Insufficient fire-escapes. 

9. Inadequate means of extinguishing a fire and of 
preventing panic. 



INDUSTRIAL FACTORS INFLUENCING HEALTH 175 

Another of the great dangers in many industrial 
estabhshments is due to the improper safeguarding 
of machinery. It has been estimated that there are 
nearly 1,000,000 accidents to workers in the United 
States every year, and that several hundred thousand 
persons are disabled, while many thousands are killed 
outright, through accidental injuries in factories. 
i\Iost of these accidents can be prevented and avoided 
by the proper safeguarding of machinery; and the 
hazards of industry may be greatly reduced by proper 
care on the part of the employers and managers to 
whose care the lives of the workers are intrusted. 

The proper light and illumination of the work 
places are of great importance to the health of the 
workers. It is to the interest of the employer that the 
workman should be able to see what he is doing. It 
is to the interest of the work itself that the worker 
should not strain his eyes in the performance of his 
functions. A large number of factories and work- 
shops are improperly lighted and illuminated, causing 
injury to the eyes and general health of the workers. 

The provision of sufficient air in workshops is of 
the utmost importance to the health of the worker. 
Labor in confined rooms is injurious to the health, 
does not furnish sufficient oxygen to the body, com- 
pels the worker to inspire deleterious substances, and 
predivSposes him to various diseases, especially tuber- 
culosis. During work more air is needed than during 
repose, and it is of the greatest im])(M'tance that work- 
shops should be well ventilated and the air therein 
be of a pr()i)er temperature, not overheated, and 
fre(iuently changed. 



170 HYGIENE OF OCCUPATIONS 

While it is possible to ])rovi(le adequate ventilation 
in homes and dwellings by natural methods of ventila- 
tion, such as windows, doors, transoms, and occasionally 
sj)e('ial devices, it is of the utmost difficulty to })rovide 
adequate ventilation in factories and workshops by 
these methods. In all factories and worksliops there 
should be provision nuide for artificial ventilation by 
mechanical means, which should allow the entrance 
of a lar^c \()luine of air into the workshops without 
draughts, and every effort should l)e made to insure 
an ecjuable tem])erature in the workshops. 

The general sanitary cleanliness of factories and 
workshops is imjjortant to the health of workers. 
There should be provision for an adequate number of 
wash rooms, dress rooms, lunch rooms, emergency and 
rest rooms, as well as insurance for the cleanliness of 
the walls, ceilings, floors, and windows; for the proper 
disposal of rubbish and garbage; the prevention of 
spitting on floors, and provision for toilet accommo- 
dations and their cleanliness. 

Working Conditions. — Besides the personal factor 
and the influence of the place of work there are many 
other conditions in industrial life which have a dele- 
terious influence upon the health of the worker. Among 
the most important of these conditions are : 

1. Too glaring light. 

2. Too great relative humidity of the air in the shops. 
.3. Extremes in temperature. 

4. Improper positions and attitudes during work. 

5. Great differences in the air-pressure. 

6. Too prolonged w^ork and exertion and consequent 
overfatigue. 



i 



SPECIFIC OCCUFAriOXAL DANGERS 177 

7. Insufficient })auses during work. 

8. Too great tension and physical or mental strain 
during the work. 

9. Last but not least, inadecjuate compensation of 
the workers. 

The other injurious influences to which the industrial 
population is exposed are improper standards of living, 
ignorance of personal hygiene, the unsanitary housing 
of the working classes, improper feeding, etc. 

SPECIFIC OCCUPATIONAL DANGERS. 

There are certain specific dangers found in many 
trades and industries. These dangers are mostly due 
to the materials which may be grouped as follows : 

1. Infectious materials. 

2. Dusts. 

3. Poisons, gases, and fumes. 

Infectious Materials. — Certain materials, like, gar- 
ments, underwear, rags, etc., may be infected with 
the germs of scarlet fever, typhoid, diphtheria, etc., 
and spread infection to the workers. Gardeners may 
be infected with tetanus; horsemen and coachmen 
with glanders; tanners, wool-workers, etc., with an- 
thrax; nurses with the various communicable diseases 
of the persons of whom they are taking care; tunnel 
workers with ankylostomiasis. 

Dusts. — There are many industries in which a great 
amount of dust is created during the work. The effects 
of the dust ui)()n health vary with the amount of dust 
inhaled, the kind and character of the dust, the period 
of exposure, the individual health of the worker, and 
12 



178 llYdlESE OF OCCUPATIONS 

many otluT factors. All dusts cause sonic irritation 
to the nuicous membrane of the eyes, nose, mouth, 
and throat. Metal or mineral dusts may also cause 
mechanical injury to the mucous membranes of the 
resj)iratory i)assages. 

lloiVnian classifies dusty trades accordin*^ to the 
dust })r()duced, as follows: 

(Jhoip ].' K.rposiiif/ to McidUic Dust: (irinders, i)ol- 
ishers, tool- and instrunicnt-niakcrs, jewellers, gold- 
beaters, brass-workers, printers, c()mj)()sit()rs, engravers, 
pressmen. 

(Jiiorr \\.- K.vpos'nui to MincrdI Dust: Stone-, 
marble- and cement-workers, glass-cutters, diamond- 
cutters, potters, ])lasterers, paperhangers, molders, 
core-makers, lithographers. 

Group III. — Exposing to Animal and Mixed Dust: 
Furriers, taxidermists, hatters, silk-, wool-, and w orsted- 
workers, carpet-, rug,- rag-, and shoddy-workers, hair- 
mattress-makers, upholsterers, etc. 

Group 1\. — Exposing to Vegetable-fiber Dust: Cot- 
ton ginners; textile, flax, hemp, cordage, and paper 
manufacturers; weavers, spinners, hosiery knitters, 
lace-makers, jute and wood-workers. 

According to Hoffman, the mortality-rate from 
consumption varies according to each group. Thus 
the mortality-rate in metallic trades is 37.4 per cent.; 
that from organic dust is 23.7 per cent.; from mineral 
dust, 28.6 per cent.; from vegetable dust, 27.4 per 
cent.; from animal and mixed dust, 32.2 per cent.; in 
all dusty trades, 28 per cent. 

Industrial Poisons. — Many poisons are either pro- 
duced or found in industries and industrial processes. 



SPECIFIC OCCUPATIOSAL DANGERS 179 

The list of principal poisons published by the Depart- 
ment of Commerce and Labor includes over fifty, 
among which lead, arsenic, mercury, zinc, phosphorus, 
and chromium undoubtedly cause the greatest 
injury. 

Lead. — There are innumerable trades in which lead 
is used in oiie form or another, and the workers often 
suifer from lead poisoning. Lead enters the system 
chiefly through the digestive tract, but also through 
the limgs and skin. The effects of lead poisoning are 
the following: Constipation, abdominal cramps, or 
lead colic, anemia, blue line on the gums, pain in the 
joints, temporary blindness, ''wrist-drop," loss of 
motive power in hands and feet, progressive muscular 
paralysis, multiple neuritis, leading sometimes to con- 
vulsions and insanity. The workers most frequently 
affected are those who work in the lead factories and 
smelting works, printers, type-founders, lithographers, 
potters, enamel-makers, plumbers, painters, glass-, 
gold-, silver-, and patent leather-workers. The laws 
protecting workers from lead poisoning in this country 
are very inadequate. Women and children suffer 
more from lead poisoning than men, as their suscep- 
tibility to the poison is much greater. 

Arsenic. — This poison is extensively used in the arts 
and trades. Arsenic afi'ects the skin, the digestive 
tract, and the respiratory and nervous systems. The 
effects of arsenic are skin eruptions, catarrhal inflam- 
mations, colic, indigestion, nerve disturbances, pro- 
gressive muscular atrophy, etc. 

Mercury. — Mercury is used in many trades and may 
injuriously affect the workers. They come in contact 



180 HYGIENE OF OCCUPATIONS 

with it in ciuicksilver, gold, and silver mines, in the 
manufacture of barometers, thermometers, electric 
meters, in the manufacture of drugs, in the felt and 
fur industries, in the manufacture of artificial flowers, 
in powder works, in photography, and in various 
chemical works. Mercury is introduced into the sys- 
tem hy inlialatioii of the fumes, hy ingestion of the 
salts, and hy absorption through the skin. The effect 
of mercurial poisoning is manifested in stomatitis, 
gastric disturbances, a metallic taste in the mouth, 
ulceration of the gums, nerve paralysis, loss of memory, 
and other nervous disturbances. 

Phosphorus. — The danger of phosphorus poisoning is 
limited almost entirely to workers in match factories. 
Its effects are manifested in gastric disturbances and 
in caries of the teeth, and necroses of the bone of the 
jaw. Under the present federal law the manufacture 
of poisonous phosphorus matches is to be eliminated 
entirely. 

Other Poisons. — There are several other poisons which 
injuriously affect the workers. Among these the most 
important are chromium, zinc, aniline, and others, 
which are employed principally in the chemical 
trades. 

Gases, Fumes, and Vapors. — There are also many 
industries in the processes of which dangerous gases, 
fumes, and vapors are produced. Some of the principal 
gases and substances from which injuries fumes 
arise, are: Sulphuric acid, sulphuretted hydrogen, and 
other sulphur compounds; carbon monoxide, carbon 
dioxide, carbon bisulphide, and other carbon com- 
pounds; nitric acid, hydrochloric acid, ammonia, chlor- 



I 



INDUSTRIAL BETTERMENT 181 

iiie gas, iodine, bromine, petroleum, benzine, nitro- 
benzol aniline dyes, and all coal-tar products; chromium, 
potassium, alum, iron, lead, turpentine, cyanogen 
compounds, dynamite, etc. 

The dangers from gases and fumes depend on the 
toxicity of the substances, the irritating nature of the 
fumes, their corrosive action upon skin and mucous 
membranes, the danger from burns, scalds, and ex- 
plosions, and finally upon the excessive temperatures 
of the places in which these gases are generated. 

The way in which these gases enter the system differs 
from that of dusts or poisons. While dust acts prin- 
cipally upon the respiratory system, gases and fumes 
have specific action upon the eyes, mucous membranes, 
and the blood. Some of the fumes which are the prod- 
ucts of various industries act as virulent poisons, and 
their action may prove fatal within a short time after 
exposure, as, for instance, after inhaling gases like 
carbon monoxide, sulphuretted hydrogen, bromine, 
chlorine, cyanogen, etc. The effects of irritating 
gases and fumes upon the eyes, the skin, and mucous 
membranes are very marked in the numerous skin 
afl'ections, erosions of the mucous membranes of the 
nose and mouth, and the various ulcerative and in- 
flammatory changes in the skin of hands, fingers, face, 
and arms. 

INDUSTRIAL BETTERMENT. 

In order to prevent the injurious influences of pre- 
vailing industrial conditions and to })r()m()te the 
health of the workers manv of the industrial evils 



182 IIYCIEXE OF OCCUPATIONS 

which hcive been eiiuinerated must he ahoHshed by 
means of proper legislation for the protection of 
workers, strict enforcement of t\\v law, and the spread 
of education amon<^ both employers and workers. 

Many of the industrial factors which are inimical 
to the liealth of the employees are not necessary, 
unavoided, and may easily be prevented by proper 
care and thou^htfulness on the part of the emj)loyers 
or managers. Many other injurious influences can 
be avoided by special devices and protective care. 

In the following pages an attempt is made to give 
a brief summary of the vast subject of industrial 
l)etterment and workers' welfare. 

Age. — No child under sixteen is physically ripe for 
continuous muscular exercise, and no child under that 
age should be permitted to be at work in gainful 
occupation. The period of Hfe between six and sixteen 
should be devoted to physical, mental, and moral train- 
ing, growth and development, and not to the economic 
exploitation of the child. 

Sex. — There should be legislative restriction (1) of 
the kind of work women may do, (2) of their hours of 
work, (3) of their work during certain periods. 

Women's w^ork in many forms of labor, especially 
when there are abundant dusts, specific poisons, and 
extra hazardous machinery, should be either entirely 
prohibited or greatly restricted. The consensus of 
opinion of all investigators is that eight hours of daily 
w^ork should be the limit for female labor and that 
night w^ork for women should be entirely prohibited. 
It also goes without saying that women should not 
work during pregnancy or during lactation, and that 



ISDVSTRIAL HF/rTERMENT 183 

special i)r()\isi()ii should be made for women (luring 
their monthly semipathologieal periods. 

Home Work. — Home work is at })resent greatly re- 
stricted in many States. The aim should be to abolish 
it entirely, as the home should not be converted into 
a workshop. 

Selection of Trade. — AVith a proper system of primary 
and industrial education and vocal guidance, the 
selection of a proper trade in conformance with the 
physical condition of the worker would be greatly 
facilitated. A rigid preliminary physical examination 
by competent medical examiners would prevent the 
entrance of the physically unfit or of weaklings into 
a trade which requires robustness, great physical 
power, and endurance. 

Education. — The education of workers in matters 
of personal hygiene, in the protection of their own 
health and lives, and in the avoidance of the injurious 
influences of industry, would be a great gain and 
would prevent many industrial diseases and resultant 
evils. 

The Work Place. — The sanitation of the work place is 
of the utmost importance to the worker and should 
be under the supervision of State authorities, who 
sliould require a license for the establishment of fac- 
tories and workshops. The licenses should be con- 
ditioned upon the ])roper construction, size, plan, 
and arrangement of the buildhig. The walls, floors, 
ceilings, and all other surfaces in factories should be 
smooth, without crevices, nooks, corners, moldings, 
etc., and should be finished with some non-absorbent, 
light-colored material, easily washed ofl' and cleansil)le. 



1.S4 IIYGIEXE OF OCCrPATIOXS 

Sixjcial care should bo given to fire protection and 
the avoichince of dan«2:ers from fires and j)anics. The 
height of the l)uilding.s in which factories are h)cated 
should he limited, and the number of occupants on 
each floor should be limited also. The construction 
of all buildings where a large number of workers are 
congregated should be absolutely fireproof, with an 
installation of all modern fireproof devices, such as 
automatic fire s])riiiklers, extinguishers, etc. There 
should be am])lc means of exit, which should be en- 
closed in firej)roof ])artiti()ns, and there shoukl be on 
every floor a zone of safety to which the workers may 
escape to remain there for a certain period during fire 
or ])anic. Frequent fire drills are also necessary in 
order to insure discipline among the workers and to 
pre\ent panics. 

The provision for proper light and illumination of 
factories should be in the hands of capable illuminating 
engineers, and the intensity of light for a given place 
should be properly calculated according to the various 
exigencies of each trade. Artificial illumination should 
be controlled so as to avoid the glare which is likely to 
injure the eyes of the workers or to cause undue eye- 
strain. 

Special provisions for insuring the purity of the air 
in shops should be taken by compulsory provision of 
artificial illumination and ventilation in all factories 
where a large number of persons are at work. 

The greatest care should be taken in providing 
ample washing facilities, a pure water supply, a suffi- 
cient number of dressing rooms, and properly cleaned 
and w^ell-flushed toilet accommodations. 



INDUSTRIAL BETTERMENT 185 

The cleaning of the work rooms should he the duty 
of specially apix)inted persons, and should he carried 
out by methods which prevent the raising of dust and 
insure cleanluiess in the shops. 

There should also be some provision in especially 
large factories for rest rooms, emergency rooms, first- 
aid and hospital service, and also for lunch rooms and 
some forms of periodic recreation. 

Prevention of Specific Occupational Dangers. — To 
prevent industrial infection from hair, hides, clothing, 
etc., all suspected material must be thoroughly dis- 
infected and fumigated, and the employees must be 
taught to take proper precautions in handling such 
products by explaining to them the modes of infection. 

Prevention of Dust. — The evil effects of dust in in- 
dustry may be prevented by the following measures: 

1. Separation of the dusty processes from the less 
dust-producing processes and the isolation of these 
dusty processes in specially constructed rooms. 

2. The instant and continuous removal of all dust 
created at the place of production, by special vacuum 
hoods and tubes covering every dust-producing pro- 
cess, all dust being exhausted by fans operated by 
one central motor. 

3. Substitution of machinery for handwork in all 
processes where the workers are exposed to dust and 
where mechanical means, which w\\\ cover the dusty 
process and prevent the dust from coming in contact 
with the workers, cannot be devised. 

4. Substitution of the wet method for dry ])n)duc- 
tion, that is, all materials i)r()(lu('ing dust, should be 
well moistened during the process of manufacture. 



18G HYGIENE OF OCCUPATIONS 

5. By isolating]: tlie worker from the dusty process. 
This may he accomplished hy separating]; the worker 
from the fhist-pnxhiciiijj: ])rocess hy a glass or other 
partition or screen, and hy inducing each worker to 
wear properly adjusted resj)irators in order to prevent 
the entrance of the dust into the nostrils and mouth. 

Prevention of Poisons, Gases, and Fumes. — The ])re- 
vention of the effects of industrial ])()isons, gases, and 
fumes does not differ in principle from the prevention 
of injury from dust. There are a number of poisons 
for which non-toxic substances may easily be sub- 
stituted. This has been done already in a number 
of cases. Yellow phosphorus, now prohibited in 
manufacture, has been replaced by red phosphorus; 
nitrate of silver has been substituted largely for 
mercury in the manufacture of mirrors; and in pottery 
production a leadless glaze is now being introduced. 
The removal of gases and fumes may easily be accom- 
plished by means of proper ventilating devices. 

Prevention of Accidents. — The prevention of accidents 
due to machinery and other causes is a most important 
part of industrial hygiene. Motors, engines, and fly- 
wheels should be fenced in and provided with proper 
guards and rails. Wheels, shafts, drums, belts, gear- 
ings, etc., should be enclosed and protected by special 
devices. There should be in every establishment a 
rigid inspection by the foreman and by experts in the 
proper safeguarding of machinery. 

Factory Inspection. — Factory inspection is already 
a recognized State institution, and has done much 
toward the amelioration of the conditions of labor. 
In order to increase its benefits, part of the control 



IXDVSTRIAL BETTERMEXT 1^7 

of iiidustrit's should \)v in the hands of qualified physi- 
cians. Me(h*('al factory inspection is a demand of 
modern industrial hygiene no less than medical school 
inspection. Comprehensixe medical factory inspec- 
tion embraces the following features: State licensing 
of trades and industrial establislmients; preliminary 
physical examination of applicants for employment; 
periodic medical inspection and examination of workers; 
exclusion of all who are physically unfit or suflfering 
from incipient disease; sanitary inspection of places, 
of trades, and all sanitation. ^ledical factory inspec- 
tion is already established in many European countries, 
where its great value in relation to public health has 
already been recognized. 

Public control of environmental conditions, improve- 
ments in the housing of the working classes, spread 
of education, better systems of popular nutrition, and 
similar sanitary improvements are already included 
in the duties of social workers and form a part of public 
health progress. 

Health Insurance. — Finally, the promotion of public 
health demands the institution of new measures 
for the protection of the workers, as well as the general 
community, by means of compulsory industrial insur- 
ance. Insurance against accidents, against sickness, 
against death, against unemployment, and similar 
insurance is already in vogue in many countries, 
and this principle is rapidly spreading and promises 
to become one of the most important elements in 
industrial legislation and industrial welfare. 



188 HYGIENE OF OCCUPATIONS 

FUNCTIONS AND DUTIES OF THE FACTORY 
NURSE. 

The recognition of the im])ortance of the human 
factor in modern industry lias led owners of industrial 
establishments to improve the sanitary conditions of 
their factories and to take better care of their employees. 
A large number of factory owners have appointed 
physicians as sanitary supervisors of their plants and 
medical examiners of their workers, and advisors and 
consultants in the p^^^•ention of occupational and voca- 
tional diseases. 

The trained nurse is also playing a very important 
role in factory sanitation and in the field of industrial 
hygiene. A large number of nurses have been and are 
constantly being appointed in various plants to assist 
the physicians in their work of increasing the health 
and efficiency of the workers. 

The functions and duties of the factory nurse are as 
follows : 

1. First-aid and emergency treatment. 

2. Care of the health and physical condition of women 
workers. 

3. Inspection and supervision of sanitary comforts, 
lunch rooms, recreation, etc. 

4. Investigation of causes of absence of workers. 

5. Visits to the homes of workers and hygienic advice 
to their families in their homes. 

Perhaps the most important function of the factory 
nurse is the giving of first aid for minor accidents in 
the shop and treatment and advice given to women 
workers for slight ailments, etc. 



FUXCTIONS AXD DUTIES OF FACTORY NURSE 189 

A number of industrial codes make legal provision 
for nursing service and for the provision of first-aid 
kits in the factory. The New York Industrial Code 
provides for a first-aid kit in every factory employing 
more than ten persons in which power-driven machinery 
is used for manufacture. 

The first-aid kit must be made of metal or glass, and 
be dustproof. The contents of the kit are: 

Instruments: Scissors, forceps, tourniquet. 

Drugs : Aromatic spirits of ammonia. 

Four per cent, solution of boric acid. 

Tincture of iodine. 

Collapsible tube of vaseline with bicarbonate of 
soda. 

Castor oil. 

Various dressings. 

The first-aid box will naturally vary according to the 
character of the industry and work done in the shop. 

The prompt treatment of small wounds and injuries 
by the nurse by application of tincture of iodine and 
suitable measures in slight burns, eye injuries, etc., 
are not only a great saving to the employer by pre- 
vention of compensation cases, but also a means of 
preventing serious effects upon the health of the 
workers. 

The time is not far distant when every modern fac- 
tory will employ at least one nurse for every one 
hundred or one hundred and fifty employees in the 
establishment. 



CHAPTER VI. 

INFPXTIOUS DISKASES AND THEIR 
PREVENTION. 



I. General Considerations: The Infectious Diseases — Classification 
— Stages — Morbific Agents — Portals of Entry — Modes, 
Vehicles and Agents of Transmission. 

II. Principles and Practice of Prevention: Mortality — Progress in 
Prevention — Methods of Prophylaxis — Individual Immunity, 
etc. — Disinfection — Social Mea.sures of Prophylaxis. 

III. The Role and Functions of the Nurse in Prevention of Infectious 
Diseases: Public Health Nursing — District Nurses — Nursing 
in Tuberculosis — Measles — Scarlet Fever — Diphtheria — Pneu- 
monia — Typhoid — Poliomyelitis — Erysipelas. 



GENERAL CONSIDERATIONS. 

Diseases are divided into two principal groups, 
constitutional and environmental. 

Constitutional diseases are such as are due to organic 
and structural defects in the body organism, such as 
diseases of circulation, digestion, metabolism, etc. 

Environmental diseases are due to extrinsic factors, 
external interference and to the invasion of the body by 
morbific agents. 

The prevention of constitutional diseases is within 
the scope of personal hygiene. 

The prevention of environmental disease is within 
the functions of public hygiene and sanitation, because 
the etiological environmental factors are those which 
usually act in large groups and upon large masses of 



GENERAL CONSIDERATIONS 191 

people, and also because the pre\eiitioii of such dis- 
eases is only possible with the help and cooperation 
of the whole community. 

The most important en^'i^onmental diseases are 
those which are ^•ariously termed infectious, com- 
municable, contagious, pestilential, parasitic, zymotic, 
etc., but which are all included under the one term 
communicable diseases. 

The following is a list of communicable and mfectious 
diseases, alphabetically arranged : 

Actinomycosis. 

Anthrax. 

Chicken-pox. 

Cholera. 

Dengue. 

Diphtheria. 

Dysentery : 
(a) Amebic. 
(6) Bacillary. 

Favus. 

German measles. 

Glanders. 

Gonococcus infection. 

Hookworm disease. 

Leprosy. 

Malaria. 

Measles. 

Meningitis: 

(a) Epidemic cerebrospinal. 
(6) Tuberculous. 

Mumps. 

Ophthalmia neonatorum. 



192 IXFECTlOiS DISEASES AND PREVENTION 

Paratyphoid fever. 

Plague. 

Pneumonia (acute). 

Poliomyelitis (acute infectious). 

Rabies. 

Rocky Mountain spotted or tick fever. 

Scarlet fe\er. 

Septic sore throat. 

Smallpox. 

Syphilis. 

Tetanus. 

Trachoma. 

Trichinosis. 

Tuberculosis (all forms, the organ or part affected 
in each case to be specified). 

Typhoid fever. 

Typhus fever. 

Whoopi ng-cough . 

Yellow fe\'er. 

The majority of the communicable diseases have been 
found to be caused by the entrance into the body of 
certain microorganisms of animal and vegetable origin. 
These microorganisms live, develop, reproduce, in- 
crease and multiply within the body or the body organs 
and either directly destroy vital tissues and important 
organs or evolve certain toxic products which interfere 
with proper body metabolism or cause pathological 
changes constituting the specific symptoms and signs 
of the various diseases. 

The chief characteristic of most of these diseases is 
that they are communicated and transmitted from one 
person to another person either directly or indirectly, 



GENERAL CONSIDERATIONS 193 

l)\' coutiict or through the mecUum of certain objects, 
in one wa\' or another, or in several ways combined. 

The communicable diseases are classified according 
to the shape, characteristics, and character of the 
morbific agents which cause them, or according to 
prominent symptoms or groups of s}Tnptoms, skin 
lesions, etc., which each or certain groups represent, 
or according to the mode, vehicle and agent of trans- 
mission. 

Infectious diseases are characterized by having cer- 
tain stages, such as exposure, infection, invasion, 
incubation, acme, decline, etc. 

The stage of exposure is the time during which the 
person is exposed to the presence of morbific agents. 

The period of infection is the period of actual entrance 
of the morbific agents into the organism or system. 

The stage of incubation is the period of actual devel- 
opment of the morbific agents within the organism, 
or the period of the active struggle for existence between 
the infecting agent and the defensive forces of the 
body. 

The period of invasion is the period during which 
the infecting morbific agents, having won their battle, 
the definite symptoms of disease (the prodromal 
stage), begin to manifest themselves. 

The stages: acme, decline, and convalescence, are 
characterized by the height, the decline of disease, 
and recovery. 

The degree of infection depends upon the number of 
morbific agents, their virulence, the mode of entrance, 
and the vital resistance of the body. 

The incubation period depends uj)()n the s|XH'ific 
13 



194 IXFECTIOUS DISEASES AND PREVENTION 

character of the invading morbific agents, and varies 
with chffereiit diseases. 

Decline of the (h'sease is either sndden, by rr/,v/.v, or 
grafhial l)y h/.sis. Convalescence may also be delayed 
by "recnrrence" or ''relapse." 

The disease may also be of acute, subacute, or chronic, 
severe or mild, remittent or intermittent. 

Infectious diseases are termed endemic when they 
a])])car continuously in one locality, epidemic when they 
afi'ect a large number of ])crsons at one time, and pan- 
demic when the\" co\er a vast area of land or several 
countries. 

The three most important features of infection and 
infectious disease are the following: 

1. The morbific agents. 

2. The portals of entry. 

'^. Modes, vehicles, and agents of transmission. 

1. Morbific Agents. — The belief that certain dis- 
eases are caused by some living agents outside of the 
body is old and has been held b}^ many ancient ob- 
servers, but the proof has only become possible after the 
perfection of the microscope and with the extensive 
research into the microorganic world which this instru- 
ment has made possible. 

To Pasteur, of France, and to Koch, of Germany, 
we owe the establishment upon a scientific basis of the 
new science of bacteriology, to the researches in which 
we owe the definite proof that certain diseases are 
directly caused and are due to specific microorganisms, 
which invade and infect the human body and, by their 
activity and products, cause the pathological changes 
and train of symptoms which we call infectious diseases. 



GENERAL CONSIDERATIONS 195 

The microorganisms which act as morbific agents of 
disease are of animal or vegetable origin, mostly of 
the latter. 

The animal parasites belong to the protozoa, insects 
and worms. 

The vegetable microorganisms are grouped under the 
general group of bacteria, which signify minute uni- 
cellular plants and which are subdivided into a number 
of groups and types; one important subdivision being 
according to their external form; thus, the cocci are 
so named because of their spherical form, the bacilli 
have a rod-like elongated form, while the spirilli have 
a spiral form. 

While millions of these vegetable microorganisms are 
entirely innocuous, there are among them certain species 
which, entering under favorable conditions into favor- 
able soil in the human organisms, become pathogenic 
and are to be looked upon as the morbific agents of 
disease. 

Among the more important pathogenic cocci are 
the following: Staphylococcus pyogenes aureus, Strep- 
tococcus pyogenes, pneumococcus, and the gonococcus. 

The following are some of the pathogenic bacilli: 
Bacillus anthracis, Bacillus edematis maligni. Bacillus 
tetani, Bacillus typhosus, Bacillus tuberculosis. Bacillus 
mallei, Bacillus lepra, Bacillus diphtherise, Bacillus 
influenztT, Bacillus coli communis. 

Among the spirilla the following are noted: Vibrio, 
cholera Asiatica, s])irillum of relapsing fever, Spiro- 
cheta pallida (Treponema })allidum). 

Bacterial Diseases. — vSome of the diseases, the mor- 
bific agents of which iiave already been demonstrated, 



196 INFECTIOUS DISEASES AND PREVENriON 

are the following: Septicemia and pyemia, pneumonia, 
gonorrhea, anthrax, malignant edema, tetanus, typhoid 
fever, tuberculosis, bubonic plague, diphtheria, influ- 
enza, cholera, relapsing fever, yellow fever, malaria, 
syj)hilis, etc. 

Some of the diseases which are infectious, but the 
specific agents of which have not yet been absolutely 
demonstrated, are the following: Scarlet fever, measles, 
smallpox, rabies, pertussis, etc. 

The pathogenic action of the morbific agents upon 
the body may be due partly to mechanical, partly 
biological and partly chemical action. 

The very presence of the mobific agents may mechani- 
call}' interfere with the physiological action of certain 
organs, causing stasis, hemorrhage, etc., or the in- 
creased activity of the morbific agents may cause 
local inflammation of tissues, infiltrations, and abscesses 
or the whole body may be infected by metastatic foci 
by means of blood or lymph, thus carrying infection to 
remote parts. 

Much of the harm done is not by morbific agents 
themselves, but by their chemical products, or toxins 
which are the results of the bacterial action upon the 
blood and body fluids as well as to other bacterial 
products, endotoxins, proteins, etc. 

These toxins are not as yet all known, and vary in 
their effects and virulence according to various 
factors. 

2. Portals of Entry. — Infection of the body with 
microorganisms is by means of entrance of these or- 
ganisms into the body through certain portals of entry 
which differ with each specific bacterium, so that some 



GENERAL CONSIDERATIONS 197 

bacteria may be entirely innocuous when entering a 
certain organ of the body, while pathogenic and viru- 
lent when entering another part or organ. 

The principal ports of entry are the skin, the respira- 
tory, the alimentary, and the genito-urinary tracts 
of the body. 

While some microorganisms may enter the healthy 
and normal skin, this is very rare, and the commonest 
mode of entrance is through some solution of continu- 
ity, through cuts, bruises, abrasions, wounds, etc. 

The skin as a port of entrance admits certain animal 
parasites, like favus, scabies, tinea, tonsurans; also 
through bites of insects in malaria, yellow fever, plague, 
through wounds, etc., in s}T)hilis, septicemia, small- 
pox, etc. 

The respiratory tract as the port of entrance admits, 
through the mucous membranes of the nose, eyes, ears, 
mouth, and throat, diphtheria, scarlatina, measles, 
influenza, pneumonia, etc. The throat, bronchi, tra- 
chea, larynx, and lungs may be the port of entrance of 
tuberculosis, diphtheria, pneumonia, influenza, per- 
tussis, etc. 

The alimentary canal as the port of entrance is open 
to typhoid, cholera, dysentery, etc. 

The genito-iu-inary tract as the port of entrance is 
entered by gonorrhea, syphillis, chancroid, tuberculo- 
sis, diphtheria, septicemia, etc. 

The different parts and tissues of the body react 
variously to microorganisms, while the various micro- 
organisms have each a predilection for certain parts 
of the body, in some of which they thrive, while in 
others they succumb. 



198 INFECTIOUS DISEASES AXD PREVENTION 

?). Modes, Vehicles and Agents of Transmission of Infec- 
tious Organisms, 'i'lir patho^^^cuic hactcria arc not 
found free in nature, hut tlioy live in the hody, the 
blood, the secretions and excretions, the discharges of 
the body, the skin and the exterior of persons which 
they infect. Hence the principal agents of infection 
as well as vehicle of transmission, are man liimself 
and animals, and their discharges. 

The morbific agents arc found in the various parts 
and discharges of the body. Thus, certain bacteria 
may be found on the skin, in the secretions of the eye, 
ear, nose and throat, the sputum, the expectoration, 
the persj)irati()n of the skin, the urine, the solid excreta, 
the secretions from wounds and abscesses, etc. All 
the above-named secretions and excretions may con- 
tain virulent morbific agents which may be trans- 
mitted from one individual to another. 

The transmission of bacteria may be direct, or in- 
direct, by contact or by intermediary agents and 
vehicles. 

Anything and anybody that may take up part of 
the secretions and excretions from an infected person 
and carry them to a non-infected person may serve 
as vehicle and agent of infection. Persons, animals, 
insects, food, milk, water, air, soil, and fomites may 
be then regarded as vehicles of infection. 

The most frequent and demonstrated mode of infec- 
tion is by direct contact of disease with the healthy, 
of the persons surrounding the infected ones, such as, 
physicians, nurses, etc. 

Insects and animals may be the sources, the vehicles, 
and the intermediate hosts of infection. 



GENERAL CONSIDERATIONS 199 

Animal sources of infections are traced in glanders, 
anthrax, and other infectious animal diseases, in favus, 
scabies, etc., or through bited, as in rabies, plague, etc. 

Animal vehicles of infection may serve in almost all 
infectious diseases, the morbific elements of which they 
may carry from diseased to healthy upon their bodies, 
or by means of parasites upon them, such as fleas, 
bugs, etc. 

Insect sources of infection carry infective material 
upon their bodies, legs, and wings, and deposit the 
same infective materials upon the bodies of healthy 
persons, on their mucous membranes, on wounds, in 
the food, milk, water, etc. 

It has been clearly demonstrated that insects — flies, 
fleas, lice, bugs, roaches, etc. — may and do transmit 
infective material from cholera, typhoid, tuberculous 
and other patients, and are capable of carrying infec- 
tion to healthy persons, either indirectly to foodstuff's, 
directly by means of their bites. 

That some insects, notably the mosquito, may be- 
come the intermediary hosts of several infectious 
diseases, has been demonstrated in the case of malaria, 
of yellow fever, and of elephantiasis. 

In these diseases the infective parasite is sucked up 
from the blood of a human being by the mosquito, 
and within the body of the insect the infective agent 
undergoes further development, after which it may 
cause the disease when inoculated by the bite of the 
mosquito into a healthy person. 

The spread of infection by food has also been demon- 
strated, and is an accepted fact. 

Meat, milk, and other articles of food may become 



200 INFECTIOUS DISEASES AND PREVENTION 

contaminated with infective material containing mor- 
bific agents, and such food and food products may 
upon ingestion })y liealthy ])ers()ns cause certain in- 
fectious (hseases. Tliis is the case especially with 
those diseases the morbific agents of which have their 
port of entry in the digestive tract. 

The germs of typhoid, cholera, dysentery, and prob- 
ably tuberculosis are those which, if carried into the 
alimentary canal by various articles of food, may 
cause those diseases. 

Infection may also be carried by fruit, vegetables, 
bread, milk, water, candy, and other food articles 
which are used without cooking, and which may carry 
infective material from the diseased to the healthy 
persons. 

The soil as a source and vehicle of infection is claimed 
in plague, cholera, and other diseases, but its direct 
connection with diseases, except through the means of 
infected water, has not been directly demonstrated, 
except in hookworm disease. 

Air as a vehicle of infection may serve through the 
medium of dust floating in the air, or through the drop- 
lets which are exhaled and expired by the tuberculous 
patients. 

Infection by Fomites. — By fomites are understood 
various articles and substances in use by man which 
may carry infectious material -and thus serve as vehicles 
of infection. Money, clothes, rags, bedding, underwear, 
books, mail, and the thousand and one other articles 
used by diseased persons, may be in use or handled by 
sick persons, may contain discharges from patients and 
may carry these from them to healthy individuals. 



PRINCIPLES AND PRACTICE OF PREVENTION 201 

The importance of fomites has l)een greatly over- 
estimated, owing to the misunderstanding of the exact 
nature of morbific agents and their activity, and it is 
at present claimed that fomites have nothing to do in 
the case of some diseases, while their importance in 
others has been also overrated. 

PRINCIPLES AND PRACTICE OF PREVENTION. 

Nearly one-third of all the deaths caused by all 
diseases is due to the diseases termed infectious or 
communicable. 

The mortality statistics of the last census show that 
the death-rate from all causes per 100,000 population 
was 1588.5. The death-rate from only 11 of the 
infectious diseases w^as 425, as follows: 

Tuberculosis of the lungs 154.7 

Pneumonia 155.4 

Diphtheria 27.7 

Typhoid fever 23 . 3 

Influenza 20.4 

Scarlet fever 10.5 

Whooping-cough 10.5 

Measles 9.9 

Dysentery 8.2 

Malaria 4.0 

Smallpox 1.3 

If we add to these the 113.8 deaths due to diarrhea 
and enteritis, mostly infectious, the percentage of 
infectious diseases will exceed one-third of all the cases 
of death. 

Infectious diseases may also be termed prrventahJe 
diseases. In the progress of hygiene and public health 
there has been practically in all countries of the 
world a steadv, rcirular and decided reduction in the 



202 INFECTIOUS DISEASES AND PREVENTION 

mortality from infectious diseases. Tlie last rnited 
States census has shown a decided lowering in the death- 
rate from all epidemic diseases. This is specially 
noted when the mortality for individual diseases is 
considered. 

In the very short period between 1900 and 1909 the 
death-rate from tuberculosis of the lungs in 1909 is 
shown to have been only 7'.\X) {)er cent, of that in 1900. 
The death-rate from tuberculosis of the lungs in the 
I nited States JJegistration Area has been reduced 
from over 17.") in 1()0,()()() in 1900 to less than 125 in 
191.*^. According to another table, the percentage of 
decrease in the death-rate from pulmonary tuberculosis 
in the jxM'iod between 1S90 and 1912 was not less than 
4S.9. 

The percentage of decrease from typhoid fever has 
been shown to be 65.2 between the years of 1890 and 
1912. Between the period of 1881 to 1915 the death- 
rate from typhoid fever in America has decreased 
from nearly (io per 100,000 population to about 11. 
The decennial rate w^as 51.9 for the period from 1881 
to 1890; 39 for the period of 1891 to 1900; and 29 for 
the period of 1901 to 1910. 

The mortality-rate from diphtheria and croup has 
been reduced in the United States Registration Area 
in the period of 1900 to 1914 from over 40 per 100,000 
to less than 20. 

In certain countries, for instance, the cities of Den- 
mark, the mortality-rate from diphtheria and croup 
has been reduced from 134 per 100,000 population in 
the pre-antitoxin period, to only 7.9 during the anti- 
toxin period. 



PRINCIPLES AND PRACTICE OF PREVENTION 203 

Perhaps no greater progress has ever l)eeii sliowii in 
progress of hygiene than is exempHfied hy the reduc- 
tion in niortahty of such preventable diseases as small- 
pox and }ellow fever. 

Smallpox has been reduced from one of the most 
deadly diseases to one of the most negligible. In cer- 
tain countries, for instance, as in Prussia, it has been 
practically wiped out. In New York City there were 
only 2 cases of smallpox in 1916. 

Since the discovery of the communication of yellow 
fever through the bite of an infected mosquito, this 
disease, which was so greatly dreaded in certain parts 
of the country, has become practically extinct. 

Methods of Prophylaxis. — The methods of prevention 
of infectious communicable diseases may be divided into 
two groups, individual and social. 

Individual Methods of Prophylaxis. — The methods 
of prevention which have the purpose to safeguard the 
individual from becoming a prey to infectious diseases 
may be grouped as follows : 

1. Increasing the individual resistance and immunity. 

2. Artificial immunity. 

3. Destruction of morbific agents and carriers of 
infection. 

Immunity. — Not all persons are equally susceptible 
to the action of morbific agents and their products. 

The normal body, animal as well as human, possesses 
a certain natural immunity, or resistance, to the action 
of bacteria and their toxins. This vital resistance has 
been defined by Sedgwick as "that condition of the nor- 
mal body, j)lant, or animal in which it is able to cope 
more or less successfullv with unfa\()rable influences 



204 INFECTIOUS DISEASES AND PREVENTION 

acting upon it from witliout, v. c, from the environ- 
ment." 

\'ital resistance a^^ainst infections diseases varies 
witli each indivichial, in varions places and with various 
times and nn(kT various conditions. It may be at 
times so low tliat the incHvidual falls an easy prey to 
the first exposure to infection, or the resistance may be 
so complete apiinst a certain infectious disease that no 
matter how great the numi)er and how virulent the 
morbific agents, nor how favorable the conditions, 
the person remains unscathed, or "immune." 

Immunity then is a state of relative or complete 
resistance of the constitution against specific disease. 

Between extreme susceptibility and complete immu- 
nity there are many degrees of partial immunity, so that 
these terms "susceptibility" and "immunity" are 
relative rather than absolute. The immunity may 
differ according to time, to season, to place, to country, 
to race, to species, to family, to age, to individual 
health, etc. 

To cite but a very few examples: White rats are 
completely immune against diphtheria; rabbits and 
guinea-pigs extremely susceptible. The white rat is 
immune against anthrax, the house rat is susceptible. 
Among races, negroes show great immunity to yellow 
fever and malaria, Japanese and Chinese to scarlet 
fever. 

Besides natural immunity, there is also an acquired 
immunity; this is notably in persons who have re- 
covered from certain infectious diseases. Familiar 
examples are smallpox, scarlet fever, yellow^ fever, also 
measles, typhoid, etc. Not all infectious diseases 



PRINCIPLES AND PRACTICE OF PREVENTION 205 

seem to ^ive ininumity to those recovering from them; 
thus persons recovering from influenza, pneumonia, 
and tuberculosis seem not only to become immune, 
but, indeed, are more susceptible than before. The 
immunity when gained may be complete for a whole 
life, or may last only for a more or less short time. 

The degrees of vital resistance and immunity vary 
as already indicated, with many factors, and in individ- 
uals with the nutrition, metabolism, fatigue, conditions 
of health, etc.; and one or more of these conditions 
either increase or decrease the natural resistance, which 
is therefore spoken of as normal or physiological vital 
resistance, or increased physiological resistance, as 
differentiated from natural and from acquired im- 
munity. 

Aritficial Immunity. — Artificial immunity is divided 
into active and passive, according as to whether the 
immunity is developed within the body possessing it, 
or is transferred to it from other animals. 

Active immunity is produced by the following con- 
ditions : 

1. Recovery from disease. 

2. Inoculation with virulent living bacteria. 

3. Vaccination with attenuated bacteria. 

4. With dead bacteria. 

5. With bacterial extracts. 

Passive immunity is conferred by antitoxins and 
serums. 

Rccovd'u from Disease. — Mention has already l)een 
mjide that recovery from certain infectious diseases 
confer a more or less permanent innnuuity. The im- 
munity is equally conferred whetlier tlie disease is of 



200 IXFECTIOUS DISEASES AND PREVESTION 

a virulent type or is ^•ery mild, liencr the exposure of 
liealthy persons to a mild form of infectious disease 
may become ])eneficial hy the inmumity conferred hy 
it against the more virulent types. As a matter of 
voluntary prophylaxis this form of innnunity is- not 
without its danti^ers. 

Iiiorulation hi/ Virulent Hdcicrid. — This is based upon 
the same principles as the innnunity conferred by re- 
co\-ery from infectious disease, and has been used in 
the inoculation by variola. It has been employed also 
in cattle pla«!:ue by inoculating the cattle with virulent 
bacteria, })ut under unfavorable conditions to the bac- 
teria (in cattle j)lague into the tough tissues of the 
tail). 

ydcrination hj/ Attenuated Bacteria. — The bacteria 
are weakened and their virulence greatly diminished by 
subjecting them to unfavorable conditions, and then 
vaccinating the body by the modified, weakened, and 
attenuated virus. 

The modification and weakening of the bacteria may 
be done by means of a previous growth in a body of a 
resistant animal, as in the case of vaccine virus, also 
chicken cholera. The modification may also be accom- 
plished by drying, as in the case of rabies virus, or by 
means of heat, as in anthrax, or in Hafkin's first cholera 
serum; other unfavorable factors, such as electricity, 
light, chemicals, etc., may also be used to weaken the 
virulence of the bacteria. 

Immn7iization hy Dead Bacteria. — Instead of using 
for the vaccines living bacteria, dead bacteria are used, 
as in Hafkin's cholera, in Hafkin's plague, or in Koller's 
typhoid virus. 



PRINCIPLES AND PRACTICE OF PREVENTION 207 

Immunization by Bacteria Products. — Finally, it 
was sought to produce artificial immunity by injecting 
into the body of bacterial products. I'his was used 
not so much for the purpose of immunization as for 
therapeutic purposes, as in the case of tuberculin 
(tuberculosis) and in plasmin (cholera, typhoid). 

Passive Immunity. — While active immunity is pro- 
duced by the persons themselves by means of the reac- 
tion of their body blood and fluid with living or dead 
bacteria and bacterial products, passive immunity is 
produced in an individual not by his own body but by 
the body of some other animal, which has been arti- 
ficially immunized, and whose blood serum is injected 
into the human being to be passively immunized. 

Thus if dead bacteria or bacterial toxins are injected 
into non-immune horses until the horses become highly 
immunized the serum of these immunized horses 
possesses certain antimicrobic and antitoxic properties, 
which act as antibacterials and antitoxins if injected 
into the human body. 

The prinri})al antitoxin serums used are those of 
diphtheria and of tetanus, the latter as a prophylactic 
measure, while the former as curative as well as pro- 
phylactic procedure. Antitoxins have also been made 
for cholera and for the plague. 

I)ij)htheria antitoxin, which has played such an 
important role in the enormous reduction of the mor- 
tality from that disease, is at present prepared in a 
large numl)er of laboratories, and it is very extensively 
used. 



208 INFECTIOUS DISEASES AND PREVENTION 

DISINFECTION. 

Destruction of Morbific Agents and Carriers of Infection. 
— Difficulties' of Destruction. — It is cvidcMit that the 
ideal means of prevention of infectious diseases would 
be the destruction of the morbific agents which have 
l)een found to be the cause of those diseases. The diffi- 
culties, however, which render this form of pr()i)hylaxis 
nnattaiiiablc arc (1) that the morbific agents of all 
infectious diseases arc not as yet known; (2) that the 
known morbific agents are microscopic, invisible to 
the eye and cannot be found without special and expert 
knowledge; (3) that the microscopic causative agents 
of diseases are ubiquitous, and found everywhere, not 
only upon the sick j)ersons, but also upon the healthy 
ones, in the air, in the dust, in the soil, water, food, 
milk, clothing, houses, indoors and outdoors, and every- 
where, so that it is difficult to find a place where they 
are not present; and (4) finally, the morbific agents are 
not found free in nature but are in close contact with 
various matter to which they cling and it is the most 
difficult task to separate them and free them from their 
surroundings. 

Where, however, the presence of morbific agents is 
suspected or ascertained it is not very difficult to destroy 
them. 

Viability of Bacteria. — Not all bacteria and morbific 
agents possess the same viability; there are certain 
conditions, like mild heat, moisture, and nutrition, 
which are favorable to their growth and development, 
while other conditions, like too low or too high tem- 
peratures, dryness, absence of nutrition, and various 



DISINFECTION 209 

physical and chemical agents, that are either iiihihi- 
tive or destructive to the bacteria. 

The destructive point of most bacteria differs accord- 
ing to the species, and this is also the case with effects 
of heat upon them. 

Some bacteria succumb to comparatively mild de- 
grees of heat (as, for instance, the spirillum of cholera 
at 125° F. for four minutes), while others resist a boil- 
ing-point a long time before being killed. This is 
especially the case with those bacteria which produce 
spores, notably the tetanus and anthrax bacilli. 

The proper means of destruction of pathogenic 
bacteria will vary, therefore, according to the kind and 
species of microorganism, and also according to the 
mediimi in which it may be found, to the places where 
it may be lodged, and to many other factors. 

Definition. — A definition of the various terms used 
in the inhibition and destruction of pathogenic germs 
will be of benefit. 

Disinfection is the absolute destruction of patho- 
genic germs or the morbific agents. 

A disinfectant is an agent capable of destroying 
pathogenic germs. A germicide is the same. 

Sterilization is the absolute destruction of all organic 
life, whether infective or not; it is therefore more 
than disinfection which destroys the germs of infection 
only. 

jhitiseptics are agents capable of inhibitin.g patho- 
genic germs without totally destroying them; a dis- 
infectant must be an antiseptic, but an antiseptic need 
not be a disinfectant. 

Asepsis is the absence or exclusion of bacteria. 
14 



210 IXFECTIOVS DISEASES AND PREVENTION 

An in.scdicifh is an agent capable of destroying 
insects; it is not necessarily a disinfectant, nor need 
a disinfectant be an insecticide. 

.1 deodorant is a substance which neutralizes or 
destroys unpleasant odors; it is not a disinfectant. 

Disinfectants arc (li\ idcd into three principal groups 
— physical, clu'inical, and gaseous. 

Physical Disinfectants. — Loir Tciiipcraturrs. — Low 
temperatures are not regarded as disinfectants, as 
they do not destroy bacteria, but only inhibit their 
action and gnnxlh. 

Sn7ill(/ht: — Sunlight is a good disinfectant, provided 
the infective materials and the germs are directly 
exi)osed to the rays of the sun. The germ-destroying 
action of the light is thought to be due to the ultra- 
violet rays. Some germs are killed by a very short 
exposure to the direct rays of the sun. Tubercle 
bacilli are killed by direct sun rays within ten to 
twenty minutes, depending on the media in w^hich 
they are located. Electric and other artificial light 
is said to have some germicidal action, but it is very 
slight in comparison to sun rays. 

Desiccation. — Desiccation is like cold, an anti- 
septic but not a germicide. While bacteria must have 
moisture as a condition of their life and growth, 
desiccation will not always kill them; especially is this 
the case with the spore-bearing germs. Koch proved 
that the spore-bearing bacteria lose their viability 
after complete drying, but complete drying is very 
rare. 

Heat. — Of the physical disinfectants, heat is the 
most valuable, the most reliable, and the one most 



DISINFECTION 211 

commonly employed. Heat may be applied as a 
disinfectant in several modes: By burning, baking, 
boiling, and steaming. 

Burning. — Burning is applicable only to materials 
and objects which are so greatly infected as to make 
any other destruction of infective agents difficult or 
impossible, or it may be applied to infected materials 
which are of so little value as not to pay for the ex- 
pense of any other method. It is not always easy to 
destroy certain infected materials by burning. Some 
objects, like mattresses, etc., infected with cholera 
or t^-phoid excreta, require a very high degree of heat, 
possible only in special furnaces, for the total and 
absolute destruction of all germs, and unless the 
objects are totally consumed and turned to ashes the 
process cannot be regarded as complete. 

Dry Heat. — Some spore-bearing bacteria are able 
to withstand very high degrees of dry heat (140° C). 
This method is only applicable to objects that are 
not injured or destroyed by dry heat, such as metal 
and glass and like materials. 

Boiling. — ]\Iost bacteria are killed at temperatures 
much below the boiling-point of water, and boihng 
for half an hour destroys most spore-bearing bacteria. 

Boiling is therefore a very valuable and efficient 
as well as inexpensive method of destroying infec- 
tive agents and materials. It is applicable to all 
objects which are not injured by the process, such as 
underwear, some kinds of clothing, textile fabrics, etc. 

Steam. — ^l^his is the most valuable and efficient 
disinfecting method. Steam kills all bacteria at 
once, while the most resisting spores are destroyed 



212 INFECTIOUS DISEASES AXD PREVENTION 

within a very short period; steiiin is also very pene- 
trating, and may he aj^plied to a greiit many ohjeets 
without injuring them. Steam may he appHed in 
a small way in convenient Koch and Arnold sterilizers 
for domestic disinfection, and in a large way for 
large ohjects in institutions and hosi)itals by special 
apparatus. 

Steam for disinfecting j)urposcs is used in two 
forms — either as saturated streaming steam, or as 
superheated steam under pressure. While streaming 
steam may he sufficient for certain objects and in- 
fected materials, the ])eiietrating ciualities of super- 
heated steam used under i)ressure, and the fact that 
such steam leaves disinfected objects dry, makes the 
latter method more valuable and efficient. 

Streaming steam is used in the disinfection of 
objects by the Arnold disinfector as well as by the 
Koch apparatus. P^or disinfection by steam under 
pressure special apparatus, called autoclaves, are used. 

Chemical Disinfectants. — Certain chemicals are cap- 
able of destroying pathogenic bacteria which come into 
contact with them. 

These chemicals may be used in solid or liquid form 
or as gases. Their disinfectant qualities depend on the 
character of their chemical constituents, the form in 
which they are used, and the material in which the 
infective agents and germs are lodged. 

The objections to chemical disinfectants are that 
most of them, to destroy infective agents, must be 
used in solutions so strong that they likewise injure 
the object to be disinfected; and, furthermore, that 
they must be thoroughly mixed wath infected objects 



DISINFECTION 213 

and come into direct contact with the infective germs, 
for otherwise their action is not destructive. It is 
exceedingly (Hfficult to disinfect properly certain 
infected objects like cholera and typhoid discharges, 
unless the chemicals are very thoroughly mixed with 
every particle of the discharges; and this is very 
difficult. • 

Carbolic Acid. — This is a good antiseptic, but a 
comparatively weak germicide. Carbolic acid is not 
applicable to disinfection of material infected with 
spore-bearing bacteria, as its action upon spores is 
very feeble. It has been recorded that some anthrax 
spores can withstand a forty days' immersion in a 
5 per cent, solution of carbolic acid (Rosenau). Xon- 
spore-bearing bacteria are killed in a solution of car- 
bolic acid of from 3 to 5 per cent. Carbolic acid has 
little penetrating power. It is largely used in solu- 
tions of 2 to 5 per cent., for washing floors, walls, 
wooden siu-faces, small objects, etc. Its range of useful- 
ness is wide, because it is not injurious to most objects. 

Cresols. — Creoline and lysol are the most commonly 
used as disinfectants of this group, although others, 
like saprol, etc., may be employed. The cresols are 
more powerful disinfectants than carbolic ac'd, and 
are used for about the same objects. 

Corrosive Sublinicite. — Bichloride of mercury is a 
valuable disinfectant, and is used in solutions of from 
1 to 2000, to 1 to 500. In the stronger solutions it 
kills germs rapidly, but because it unites and forms 
insoluble compounds with albuminous matter, cor- 
rosive sublimate loses nuich of its disinfecting property 
when ust'd for infective agents mixed with much 



214 INFECTIOUS DISEASES AND PREVENTION 

organic matter. According to Rosenau, corrosive 
sublimate kills spores in solutions of 1 to 500 after 
exposure for one hour; solutions of 1 to 1000 destroy 
non-spore-bearing bacteria within a half-hour at 
ordinary temperatures. As an antisej)tic, corrosive 
sublimate is used in medical and surgical practice in 
solutions of 1 to 2000 to 1 to 10,000. 

Liltic. — III the form of chlorinated lime, or of 
Labarracpie's solution, it is a good disinfectant for 
excreta, and is used for disinfecting privy vaults, 
cesspools, cellars, etc. It is efficient only when it is 
freshly prepared. 

A number of other chemicals are used as disinfec- 
tants, although their range of usefulness is limited 
and they are not commonly so employed. Of these 
chemicals, mention may be made of potassium per- 
manganate, ferrous sulphate, zinc chloride, copper 
sulphate, borax, boracic acid, and a number of others. 

Gaseous Disinfectants. — Gaseous disinfectants are 
more valuable than other disinfectants, because 
of their penetrating power and the possibility of 
reaching surfaces and places which are inaccessible to 
ordinary liquid chemicals. Of the gaseous disinfec- 
tants employed, the most important one is formalde- 
hyde, which has lately superseded the once very popu- 
lar sulphur dioxide disinfection. Among the other 
gaseous disinfectants sometimes used are chlorine, 
bromine, and hydrocyanic acid, but these have been 
discarded almost entirely because of their toxic nature 
and their questionable effects on bacteria. 

Sulphur Dioxide. — Sulphur dioxide is a powerful 
germicide and a good surface disinfectant; its disad- 



DISINFECTION 215 

vantages are (1) that it is not very penetrating, (2) 
that it does not destroy spore-bearing bacteria, (3) 
that it damages textile fabrics, (4) that it bleaches 
vegetable colors, and (5) that it injures and tarnishes 
metals. It is also poisonous to those handling it, 
causes injury to the mucous membranes of the eyes, 
nose and throat, and leaves a very disagreeable odor 
clinging to materials for a long time. 

Several methods of sulphur disinfection are employed. 
The pot, candle, or liquid form, also the furnace. 
About five pounds of sulphur are used for every 1000 
cubic feet of space to be disinfected. Moisture and 
heat increase the penetrating qualities of the gas and 
the value of disinfection. An exposure of twenty- 
four hours is necessary for thorough disinfection, and 
as the gas is very diffusible, precautions must be 
taken effectively to close all windows, doors, cracks, 
crevices, and other apertures found in the room. 

SulJ)hur disinfection is preferable wherever surface 
disinfection is needed and where there are few articles 
which would be damaged by it, also wherever insecti- 
cide action is demanded. 

Formaldehyde Gas. — Formaldehyde gas has very 
largely superseded sulphur dioxide as a disinfectant. 
Its main value is that while it is a good germicide it 
does not destroy fabrics and injure objects, and also 
that it is non-toxic. Formaldehyde also is only a 
surface disinfectant, and its penetrating qualities are 
not very great. Bacteria are killed immediately by 
formaldehyde on direct exposiu'e, and spores within 
an hour. It kills dried organisms as well as those in 
a moist state. Formaldehvde is not an insecticide. 



211) INFECTIOUS DISEASES AND PREVENTION 

For domestic disinfection formaldehyde is generated 
by spraying liquid formalin (which contains 40 per 
cent, of the gas) or by lieating paraform pastils or 
powder, also by means of generators or lamps. Other 
methods of e\()King formaldehyde in disinfection 
which arc used in large house and hospital disinfec- 
tions arc by means of large generators or lamps, or 
in specially constructed autoclaves under pressure, 
or in retorts without pressure. 

Disinfection of Rooms, etc.— Practical disinfection is 
a ])roc(\ss which needs scientific precision and atten- 
tion to details. It must be adjusted to the form and 
nature of infection and the infected materials and 
objects, each of which may need a different method 
of handling and disinfection. The disinfection of 
rooms and infected materials differs according to the 
disease; various methods must be employed after 
tuberculosis, ty])hoid fever, yellow fever, diphtheria, 
scarlet fever, etc. 

Room Air. — The room air needs no disinfection, for 
whatever germs may be found in the dust of the air 
in a room will settle upon the surfaces whenever the 
room is closed and left undisturbed. 

Room Walls. — The room walls if covered with 
paper may be efficiently disinfected by thorough 
rubbing with stale bread. Painted surfaces of walls 
and ceilings may be disinfected by washing wdth 3 
per cent, solution of carbolic acid or a 1 to 500 solu- 
tion of sublimate of mercury. Floors and other sur- 
faces of rooms may also be conveniently scrubbed 
w^ith hot w^ater and a solution of carbolic acid or 
subh'mate, or one of the cresols. Carpets, rugs, etc., 



DISINFECTION 217 

may be efficiently disinfected by a strong solution 
of formalin, by gaseous disinfection with formalde- 
hyde, or steam under pressure. Curtains, hangings, 
etc., within the rooms are disinfected with formal- 
dehyde, and may also be washed in boiling water. 
Wooden bedsteads may be washed with a 3 per cent, 
carbolic solution or a 5 per cent, formalin solution. 
Bedding, hnen, etc., may be disinfected by steam, 
by formalin, and also by formaldehyde. 

For the successful disinfection of rooms with a gas 
it is necessary to close all openings, cracks, and 
crevices, keyholes, etc., completely, and especially the 
crevices about windows and doors. This is done by 
means of cotton, or better, by means of gummed 
paper strips. Raising the temperature of the room 
assists disinfection. The room is then closed and all 
openings and crevices are sealed with gummed paper, 
and the room is left for at least twenty-four hours. 

Excreta, sputum, feces, and other discharges of 
infected persons must be gathered and collected in 
special glass or porcelain vessels and disinfected by 
means of the various chemical disinfectants like 
lime, cresols, carbolic acid, copper sulphate, and 
formalin. Whatever disinfectant is used it must be 
thoroughly mixed with the discharges so as to pene- 
trate them through and through, and it mu^t also be 
used in large quantities and in very strong solution. 

Feces. — Feces are disinfected by carbolic acid, 5 
per cent.; solution of chloride of lime, 5 per cent.; 
formalin, 10 per cent; or by boiling. 

Thcruiometers. — Formalin, 40 ])er cent., absolute 
alcohol. 



21S INFECTIOUS DISEASES AND PREVENTION 

Soiled Wash. — Soiled wash, according to Rosenau, 
is to be disinfected as follows: 

"It is wrapped in a sheet wet with sublimate solu- 
tion, and this placed in a sack likewise moistened with 
a germicidal liquid. The sack is ])laced unopened in 
a solution containing ',] per cent, of soft soap and heated 
to 50° (\ for three hours and left in the same solution 
forty-eight hours after it cools. If not soiled with 
albuminous matter the wash may be immersed in a 
sohition of bichloride of mercury, 1 to 1000, with the 
addition of common salt. After this preliminary 
disinfection the articles are boiled half an hour in a 
water containing: 

Petroleum 10 Rrams. 

Soft soap 250 grams. 

Water 30 liters. 

The Practice of the New York City Department of 
Health in Regard to Disinfection after Infectious Diseases. 
— Within the last year or two the New York City 
Department of Health has adopted radical views in 
regard to disinfection after infectious diseases. The 
following excerpts from the Year-book of the Bureau of 
Preventable Diseases (1916) give the details of the dis- 
infection procedure of the department, with special 
regard to the nurses' work. 

Discontinuance of Fumigation. — Premises occupied 
by persons suffering from infectious diseases were for- 
merly fumigated with formaldehyde by the Department 
of Health, and bedding removed for steam sterilization. 

From its experience, the department has concluded 
that routine fumigation as a means of disinfection of 
premises where cases of infectious disease have occurred 



DISINFECTION 219 

can be dispensed with as ineffective and unnecessary. 
It is ineffective in that, as usually performed, it does 
not destroy the disease germs. It is unnecessary for 
the reason that in recovered cases all contagion has 
disappeared from the premises by the time the patient 
has recovered. 

The discontinuance of fumigation on October 8, 
1914, in the boroughs of the Bronx, Queens, and Rich- 
mond, as a routine method of disinfection after the 
major acute infectious diseases, was not followed by any 
increased prevalence of diphtheria, scarlet fever, or 
measles. On January 1, 1915, such fumigation was 
also discontinued in the borough of Manhattan, but 
continued in the borough of Brooklyn, for purposes of 
control, and in order to test the efficiency and value 
of fumigation until August, 1915, when it was dis- 
continued there also, there being no decreased preva- 
lence of scarlet fever, and diphtheria in that borough as 
compared with the others. 

It should be understood that in discontinuing fumi- 
gation the Department of Health has laid increased 
stress upon other and more efficient methods of disin- 
fection, namely, thorough cleaning, fresh air, and sun- 
light, and particularly renovation {i. e., repainting and 
repapering), when necessary. Prior to the discon- 
tinuance of fumigation no such renovations were en- 
forced in any of the infectious diseases except tuber- 
culosis. During the first five months of 1915, 10,785 
such renovations, in addition to those for tuberculosis, 
were ordered and carried out. 

That the Department of Health was justified in its 
action is shown by the fact that there has been no 



220 INFECTIOUS DISEASES AND PREVENTION 

increase in the prevalence of the various (hseases; 
better and more efficient disinfection has been per- 
formed, and the saving to the city has been at the rate 
of about S30,000 a year. 

General Disinfection Procedure. — In (Hi)htheria and 
measles when patient recovers the sick-room is thor- 
oughly cleaned and aired. The woodwork and floors 
of the room are scruhlu'd with solution of one pound of 
washing soda to three gallons of hot water. liecom- 
mendation is made that nightgowns, sheets, etc., be 
first soaked in carbolic solution and then boiled in 
soapsuds for one-half hour. Destruction of books and 
to\'s usetl by patient is recommended. 

In cases of smallpox, typhus, cholera, plague, and 
yellow fe\'er, bedding is removed for steam disinfection. 
Otherwise there is no removal of bedding except upon 
request of the attending physician. 

In cases of poliomyelitis and cerebrospinal menin- 
gitis recovering at home there is no fumigation or 
removal of goods, but renovation may be required. In 
fatal cases or removal cases, fumigation is ordered. 

In mumps, German measles, whooping-cough and 
chicken-pox neither fumigation nor removal of goods is 
performed. 

In tuberculosis renovation of the premises is done, 
following death or removal to other address. There 
is no removal of bedding except by special request or 
when unusual circumstances connected with the case 
require that such action be taken. 

In typhoid fever disinfection is not ordered except 
upon special request, unless the circumstances of the 
case demand it. 



DISIXFECTIOX 221 

In making use of the various methods of disinfection 
the availabiUty of each, antl their inherent hmitations, 
should be kept constantly in view, as, for example, the 
fact that liquid disinfectants are only elective when the 
circimistances permit of their systematic application 
to all the surfaces to be treated, and that gaseous 
disinfectants are only of use for surface disinfection. 

The fact is strongly insisted upon that for floors, 
woodwork, and similar surfaces, soap, hot water, and a 
scrubbing brush, thoroughly used, are of greater effici- 
ency than either liquid or gaseous disinfectiints, as the 
latter are usually employed; that boiling is the best 
method for treating all fabrics or articles not injured by 
such treatment, and that full aeration and exposure to 
sunlight must be regarded as of primary importance 
in all cases. 

Inspector and nm-ses constantly repeat the injunction 
that all articles used about the patient should be boiled 
or otherwise disinfected as often as used; that all 
discharges from the nose, mouth, bladder, and bowels 
must be immediately disinfected or destroyed; and that 
these things, assisted by scrubbing, sunning, and airing 
of the sick-room, and by personal cleanliness and 
frequent hand-washing by the attendants, greatly 
lessen the danger of the disease being communicated 
to others. 

Liquid Disinfectant^ and Uses. — 1. For all body 
discharges; Freshly made chloride of lime, 5 per cent, 
carbolic acid solution, or 2 per cent, lysol solution. 

2. Woodwork and floors should be scrubbed with 
solution of 1 pound of washing soda to 3 gallons of hot 
water. 



222 IXFECTIOrS DISEASES AND PREVENTION 

3. Bed and personal linen should be immersed in 
boiling water for five minutes, or in 5 per cent, car- 
bolic solution for one hour, the articles to be completely 
submerged. 

4. For washing of floors, bedsteads, and other sur- 
faces: Soaj) and hot water apj)hed with scrubbing 
brush, or when fouling by sputum or other discharges 
has occurred, the saturation of deposited matter with 
carlK)lic solution (5 per cent.) or lysol solution (2 per 
cent.), and after thirt\ minutes wiping up with rags or 
other articles that can be ))()ilc(l or burned. 

Kinds of Disinfection Ordered. — According to the 
conditions of tlie premises the nurse may recommend: 
(1) That nothing be done; this is most exceptional, 
obtaining only in very recently renovated apartments 
and those where the patient only spent one or two nights 
on the premises; (2) that a thorough cleansing and airing 
is sufficient when the premises are in good condition; 
(3) that the patient's room be thoroughly renovated; 
the walls washed and recalsomined, repapered or 
repainted, and the woodwork and floors be washed and 
repainted; (4) that the whole apartment be renovated. 

Scrubbing Floors and Woodwork. — In all instances in 
which this is the only procedure recommended by the 
nurse, she makes every effort to induce the janitor to 
perform the work voluntarily without the issuance of 
a notice. Should she fail to obtain this result, she for- 
wards a report on the regular renovation blank making 
a report and recommendation in a manner exactly 
similar to a case in which a notice should be issued, 
except that after the recommendation the following 
statement is made: "Inasmuch as I have been unable 



SOCIAL MEASURES OF PROPHYLAXIS 223 

to obtain voluntary compliance with this recommenda- 
tion, I would further recommend that the scrubbing of 
floors and woodwork be enforced by the sanitary police." 

SOCIAL MEASURES OF PROPHYLAXIS. 

The prevention of infectious diseases must largely 
be based on social measures and public defensive 
methods. Of these defensive methods the following 
are of special importance: (1) Notification and regis- 
tration of infectious diseases; (2) isolation and quar- 
antine of infected persons; (3) hospital treatment and 
care; (4) general sanitary measures. 

In order that the sanitary authorities should be able 
to cope with infectious disease they must first know 
of its existence, hence the provisions in all sanitary 
codes for compulsory notification and report of infec- 
tious diseases. The duty of reporting lies primarily 
upon the physician treating these cases and also upon 
any other person coming in contact with them and hav- 
ing knowledge of the diseases. 

The list of diseases for which compulsory notification 
is at present demanded includes the following: typhoid, 
typhus, variola and varioloid, scarlet fever, measles, 
(lil)htheria, miliary fever, cholera and choleriform 
diseases, ague, yellow fever, dysentery, puerperal infec- 
tion and ophthalmia of the newborn (unless the con- 
finement is not made public), epidemic cerebrospinal 
meningitis, and acute anterior poliomylitis. All cases 
which are reported to the health departments are care- 
fnlly registered and a record kept, the system of regis- 
tration for all infectious diseases being uniform. 



224 IXFECTIOIS DISEASES AND PREVENTION 

In all congested communities it is important that 
persons sufVering from certain infectious diseases should 
be com])letely isolated from thosc^ who are well. Such 
isolation of infected persons should be voluntary 
wherever the population is educated and is progressive. 
As a rule, however, it is compulsory in view of the gen- 
eral ignorance as yet pre\ ailing among the population. 

The isolation may be of the patient himself, of the 
room where he lies, or of the ai)artment or house in 
which he lives, as well as of the family surrounding him. 
The degree of isolation (le])en(ls much on the disease 
and the intelligence of those who surround the patient. 
Where isolation is absolutely necessary but for some 
reasons cainiot \'er\' well be obtained, as for instance, 
in virulent cases of smallpox in crowded tenement 
houses, there may be ordered the compulsory removal 
of the patient to a hospital. The sanitary authorities 
of the community prescribe the exact form of isolation, 
order the needed quarantine of the room or house, place 
the necessary placards, and perform such other pre- 
ventive acts as are deemed good for the public health. 

The duration of isolation of the patient, etc., depends 
on the disease, and may last but a few days in a case of 
diphtheria to a few months in a case of scarlet fever. 

The treatment of infectious disease is either private 
or in hospital. There is no doubt that for the public 
good and for the thorough eradication of infectious 
diseases, hospital treatment of all cases of infectious 
diseases would be preferable, as best tending to help 
not only the patient but to prevent the spreading 
of the disease in the community; but there are still 
many objections against compulsory hospital treat- 



meat of all infectious diseases as a siiininary ineahure, 
and it must he limited hut to certain few diseases and 
to the poorest i)art of population. 

Sanitary Measure. — Certain puhlic measures are 
necessary for the prevention of the spread of infectious 
diseases. These measures consist in the control of 
public food, milk and water supplies, in the prevention 
of infections in schools, factories, by means of trans- 
portation, by commerce, maritime vessels, interment, 
etc. The public prophylactic measures adopted to 
lessen and limit infectious diseases by means of public 
water, food, and milk supplies have already been dis- 
cussed in some detail in the chapters on those subjects. 

The school as a source and field of spread of infectious 
diseases has also been spoken of, and the modern 
methods of prevention mentioned as consisting in a 
thorough system of medical school supervision. During 
epidemics it has been found necessary to close schools 
for certain periods. 

No less a prominent factor in spreading infection is 
found in the factory and industrial establishments, 
and i)ro})hy lactic measures are required to limit com- 
munication of disease in industries. The best method 
of pre\'ention would l)e proper medical supservision 
and control of all industrial establishments, with initial 
medical examination of employees, also periodical 
examination of all persons in employment and isolation 
of infected ones. 

The supervision of commerce, transportation, means 

of transit by railroads and steamships is also necessary 

for prevention of the spread of infectious diseases. The 

measures ad()])te(l for this i)urpose are the super\'ision 

15 



226 IXFECTIOUS DISEASES AND PREVENTION 

and inspection of railroads and steamships, quarantine 
between cities, States, and countries in times of epi- 
demics, the inspection and disinfection of vehicles, 
cars, baggage, etc. 

Measures for supervision of the interment of persons 
dead from infectious diseases consist in the disinfection 
of bodies, and of the means of transportation, and the 
j)rovisions against j)ul)lic funerals in cases of conununi- 
cable diseases. 



INFECTIOUS DISEASES : THE ROLE AND FUNCTIONS 
OF THE NURSE IN THEIR PREVENTION. 

Public-health nursing in general and in infectious 
diseases especially is of comparatively recent origin. 
Scarceh' fifteen years have passed since the New York 
City Department of Health engaged the first nurses to 
care for cases of diphtheria, scarlet fever, and measles, 
and during the next year engaged th^ first nurse for 
tuberculosis work. Visiting nursing was in its infancy 
in the beginning of the twentieth century. It is in full 
swing at prfesent, only a decade and a half since its 
inception. In 1902 there were only 136 visiting nurses 
in the country; in 1916 the number was over 5000. 
The nurse has become the mainstay of prophylaxis in 
infectious diseases as well as in others. Public health 
nursing has become a profession. There is hardly a 
city department having to do with sanitation and health 
that does not employ a large and ever-increasing num- 
ber of trained nurses. This is but the beginning. 
There is no doubt that the influence of the public 



INFECTIOUS DISEASES 227 

health nurse will be more and more extended and ever 
increase in the extent of its usefulness. 

The functions of the public-health nurse in infectious 
diseases are manifold and varied. They may be sum- 
marized as follows: Visits to persons suffering from 
infectious diseases; discovery of new cases; care of 
the sick at home or at the hospital; investigation of 
family, economic, and other conditions of the sick and 
those nearest to him; instruction to those who care for 
the infected person as to how to take care of the various 
discharges and other agents of communication of the 
disease; the education of the family in the proper care 
and in methods of prophylaxis; the education of the 
patient and his caretakers in the after-treatment during 
convalescence; assistance in the dispensaries, clinics, 
and hospitals in the care of ambulant and other patients; 
the placarding of the rooms and homes of infected per- 
sons; supervision of the observances of isolation and 
quarantine; orders for terminating cases and for dis- 
infection. 

The following practice of the New York City Health 
Department gives a brief review of the duties of nurses 
in infectious diseases:^ 

"District Nurses. — The district nurses supervise 
at their homes cases of tuberculosis, scarlet fever, 
diphtlicria, cerebrospinal meningitis, acute poliomye- 
litis, whooping-cough, and typhoid fever. They are 
also on duty in the tuberculosis clinics, where they 
receive patients and prepare them for physical examina- 
tion by the physician; take their temperature, pulse, 

1 The Year-book of the Bureau of Preventable Diseases, Depart- 
ment of Health, New York City, 1916. 



228 INFECTIOUS DISEASES AND PREVENTION 

respiration, weight, and height; distribute circulars of 
information in the patient's own language and issue 
instructions as to necessary sanitary precautions to be 
observed. 

''Nurfics Outfit. — When on duty in her district every 
nurse carries with her the following outfit: 

"Clinical tluMMnonictcr; watch with second hand; 
fountain j)en; history cards; cards for referring |)atients 
to clinic; circulars and hanging cards for information 
regarding infectious and contagious diseases; sputum 
})ags and j)aper naj)kins; blue clinic information cards; 
sj)utuin bottles; notification })()stal cards; certificates 
of infectious disease; school exclusion and readmis- 
sion cards; rules, Bureau of i*reventable Diseases. 

'' (leucral Duties of Dis'trid Nurses. — At the first 
visit to a case of infectious disease the district nurse 
locates the janitor and inquires if anyone in the build- 
ing is ill with any infectious disease and without a 
physician in attendance. 

"On arrival at apartment of patient she inspects 
quarantine, obtains necessary data for the history card, 
and informs family that teachers and pupils must not 
attend any schools. She determines whether case re- 
quired observation or supervision, and ascertains what 
members of the family have had the disease. 

" She delivers a hanging card of detailed instructions 
relating to the case. She post placards and takes 
cultures from the patient and other members of the 
household w^hen requested. 

" On revisits she determines if quarantine is observed 
and ascertains if secondary cases have appeared in 
the family. 



INFECTIOUS DISEASES 229 

"At the final visit she terminates the case, orders 
disinfection, and issues school certificates. 

"Nurses make all visits to cases of infectious diseases 
except those for diagnosis and the first visit to cases of 
cerebrospinal meningitis. 

"Upon arrival at the case the physician or nurse 
fills out a history card, inspects arrangements for iso- 
lation, excludes susceptible children or teachers, gives 
verbal instructions, and leaves a hanging card of 
general information about the disease. This card 
particularly emphasizes the manner in which the disease 
is spread and the steps necessary for its efficient iso- 
lation. Cases are visited sufficiently often to maintain 
proper quarantine, and are classified, according to the 
ability of the family to appreciate and maintain satis- 
factory isolation, into: 

Supervision cases, which require visits every day 
or every few days, and, 

"Observation cases, which require only occasional 
visits. 

''Occupations. — The occupations of other members 
of the family are investigated with reference to the 
character of their work. The dangers of spreading 
disease may be greatly increased because of the nature 
of the work done in the home, or because of the char- 
acter of the employment of members of the family 
outside the home. Members of the family are for- 
bidden to continue such home occupations as tailor- 
ing, dressmaking, feathormaking, etc., or to engage in 
any way in the handling of foodstufi's. 

'^Placarding. — Cases of diphtheria and scarlet fever 
occurring in tenement houses, furnished rooms and 



230 INFECTIOUS DISEASES AND PREVENTION 

boarding-houses, and two-family liouses with common 
entrance, are placarded. Tlie placard in tenement 
houses is placed on the door of entrance from the public 
hall; in furnished-room houses, boarding-houses, etc., 
on the door of the sick-room, and in the two-family 
houses with common entrance upon the door leading 
from the common hall to the infected apartment." 

Nursing in Tuberculosis. — For the })urposes of super- 
vision of all j)crs()Hs sull'ering from tuberculosis, the 
Health Department divides these cases into several 
classes : 

Class 1. Cases under the care of private physicians. 

Class 2. Cases re})()rted in tuberculosis clinics. 

Class 3. erases admitted to hospital. 

Class 4. Cases leaving the city temporaril}^ or enter- 
ing sanatoria. 

( 'lass 5. At home cases. 

Class 6. Dead cases and recovered. 

Class 7. Tuberculous school children. 

As far as the cases under the care of private physi- 
cians are concerned, the function of the nurse is limited 
to finding out whether the patients live at the address 
given and the character of the house in which they Hve. 

Cases which are reported by clinics are visited by the 
nurse, who investigates the housing conditions and seeks 
to find out all information about the patient and his 
surroundings. The nurse also takes care to induce the 
patient to visit the chnics regularly and to order dis- 
infection if necessary. 

Cases which are found as unable to take care of them- 
selves may be recommended by the nurse for forcible 
removal to a hospital. This can be only done on the 
ground that the patient is a menace to the health of 



DIPHTHERIA, SCARLET FEVER, MEASLES 231 

others. It is best for the nurse to obtain the patient's 
consent to enter a hospital. The grounds for the for- 
cible removal to a hospital of a case of tuberculosis are, 
according to the New York City Health Department, 
the following: " (a) That the patient's sputum contains 
tubercle bacilli; (b) that the patient either will not 
or cannot observe the necessary precautions as to the 
disposal of sputum; and (c) that others, especially 
children, are exposed to infection." Cases admitted 
to a hospital are given to district nurses to be investi- 
gated as to their social and financial conditions. 

The district nurse is especially valuable in the "at 
home" cases. Here there is much scope for the work 
of the nurse, for her educational work, and for the 
supervision of general sanitary conditions of the patient 
and his surroundings. The patient should be visited 
at least once a week and the nurse come in close and 
friendh^ contact with the patient and his family. The 
nurse, in her visits to the patient's home, must also be 
ever on the lookout for new cases of tuberculosis among 
the family and neighbors. 

Special care must be taken in isolating the patient 
from children and with the care of children in their 
school and outside. Sickly or anemic children in the 
home where there is a case of tuberculosis must be 
attended to and, if possible, sent to open-air schools, 
day camps, or preventoria. 

DIPHTHERIA, SCARLET FEVER, AND MEASLES. 

"Diphtheria.^ — The incubation period of diphtheria 
is from one to five days; the quarantine period is twelve 

' From the Year-book of Preventable Diseases, Department of 
Health, New York City, 1916. 



232 IXFECTIOrs DISEASES AND PREVENTION 

(lays from the onset of the (hsease, (hiring whicli time 
no hiter ciiltiires are examined. Thereafter the quar- 
antine period lasts until two successive negative cul- 
tures, })referal)ly from holh nose and throat, have been 
received. 

" If the diagnosis dcjH'nds n])on a culture jdone and 
th<' (iihure is ncgatixc the case is not considered as one 
of (lij)litlieria; cases reported by postal cards are con- 
sidered as (lij)htheria, unless otherwise requested, even 
though cultures arc negative. 

"A district nurse sees each case of diphtheria on the 
day it is referred to her. Upon her first visit, upon 
rcfjuest of the attending j^hysician, she takes a culture 
from the patient's nose or throat, unless this has already 
been done by the district diagnostician. Trial cultures 
are made from all members of the family by the private 
j)hysician or by the district nurse, with his consent, in 
order that carriers may be immunized against the 
disease. 

"If quarantine is observed or address changed, chil- 
dren or teachers who have been immunized and cultures 
from whose nose and throat are negative may return 
to school. If not immunized and no negative cultures 
have been obtained, even though the address be 
changed, school permits are not issued for seven days. 
If they remain at original address until case is termi- 
nated, school permits are not given until seven days 
after the latest case in the family has been terminated 
by the Department of Health. 

" Termination of Cases of Diphtheria. — No case is 
terminated until at least twelve days have elapsed 
from the beginning of the illness, and two successive 



DIPHTHERIA, SCARLKT FEVKIi, MEASLES 233 

cultures, preferably from both nose and throat, taken 
not less than twenty-four hours apart, do not show the 
presence of diphtheria bacilli. 

" Scarlet Fever. — Incubation period two to five days. 
Quarantine period thirty days, provided desquamation 
is complete and discharges from nose and ears have 
ceased. 

"The virus of scarlet fever is contained in discharges 
from mouth, throat, and nose; possibly also in dis- 
charges from open sores. It is most abundant during 
the period of eruption, but may persist for a long time. 
During or even after convalescence it may undoubtedly 
be given off from mucous membranes when no abnor- 
mal condition whatever is discoverable. This virus 
may be transmitted from one person to another, either 
directly, as by coughing, sneezing, kissing, or other 
actual contact, or indirectly by articles which have been 
in contact with the discharges just mentioned and are 
still infected by them. 

''How long, after contamination, fomites remain 
dangerous is not known with exactness, as the germ of 
scarlet fever has not been isolated. There is reason to 
believe that this germ is longer lived than the germ of 
diphtheria or of measles or of whooping-cough, and is 
more resistant than they are to heat, cold, sunshine, 
or moisture. The desquamation of scarlet fever is not 
believed to be an infecti\'e agent unless contaminated 
by secretions. The tendency is to concentrate our 
efl'orts on the patient and to regard the onset ])eri()d 
as by far the most important. 

"When the requirement for satisfactory (luarautine 
at home cannot ])()ssil)ly be carried out, every effort is 



234 INFECTIOUS DISEASES AND PREVENTION 

made, witli the assistance of the private physician and 
the consent of the family, to secure the removal of the 
patient to a hospital. There are very few *forced-in' 
cases. The peo])le of the city are acquiring a better 
a])i)reciation of the excellent service given them by 
tlie h()s])itals of the Department of Health. 

" When shall quarantine he lifted? Cases undoubtedly 
difl'er in the persistence of their infectivity. The best 
way seems to be to fix a mininuun period applicable 
to all cases, and to prolong this when the case demands 
it. At the present time thirty days is the minimum. 
IVIany susj^ects, where the evidence is insufficient or 
otherwise unsatisfactory, are held for shorter periods 
and with varying restrictions. 

"One great hindrance to effective work against the 
spread of scarlet fever is the difficulty of making a 
diagnosis in many mild cases. The character of the 
onset of scarlet fever is the most variable of any of the 
exanthemata. The symptoms may be so trivial that 
the patient does not suspect the nature of the indis- 
position; no physician is called. Many people, after 
exposure to scarlet fever, suffer from a sore throat, 
nothing else. A positive diagnosis here is impossible. 
Many people have a life-long immunity to scarlet 
fever; many are immune at one time and susceptible 
weeks, months, or years later. It is reasonable, there- 
fore, to suppose that there may be surface invasion 
of mucous membranes by this germ for wholly indeter- 
minable periods without the production of any local 
or general infection. 

"It is well to bear in mind that the immunity ac- 
quired from an attack of scarlet fever is not invariably 



DIPHTHERIA, SCARLET FEVER, MEASLES 235 

permanent. One meets, from time to time, cases of 
perfectly characteristic scarlet fever which give indis- 
putable evidence of a previous attack. Such cases are 
rare, and there is, of course, always a chance for error. 
One should be particularly suspicious of the accuracy 
of either the present or the former diagnosis when the 
interval between the two attacks is less than five 
years." 

Instructions to Nurses as to Their Duties in the Care of 
Measles, Scarlet Fever, and Diphtheria.^ — Upon entering 
the home, remove hat and coat and place together w^ith 
the bag in a room farthest from patient's. Remove 
from bag-, cap, gown, rubber gloves, and all other 
articles needed, such as cotton, gauze, etc. Dress in cap 
and gown. Clear patient's room as much as possible of 
all unnecessary articles. Collect and mark with adhe- 
sive the necessary utensils for patient; these are to be 
kept in patient's room. Prepare solutions for cleansing 
eyes and mouth and for irrigating nose and throat (if 
this treatment is ordered). 

Give treatment, disinfect thermometer by placing 
in pure carbolic then in alcohol. Bed and body linen 
should be soaked in chloride of lime solution (J pound 
to the gallon) for a couple of houi-s before being 
washed. 

If possible, rags should be used for nasal and throat 
discharges, they should be placed in paper bags and 
burned. The nurse should instruct member of family 
who is to care for patient about disinfecting hands in 



^ The instructions as to the duties of the nurse in contagious dis- 
eases are taken from the practice of the Henry Street Nurses' Set- 
tlement, New York City. 



lysol solution after doing anything for patient, about 
general hygiene, isohition, ventilation, diet, etc. 

When finished, nurse is to remove cap and gown, 
place in paper bag, and leave in patient's room ; soak 
hands well in lysol solution, then wash well with green 
soa]) and running water. 

At end of day, nurse's bag is ()])ene(l and j)laced in a 
fumigating cabinet, a towel saturated in formaldehyde 
is hung in cabinet, cabinet sealed, and bag removed the 
next morning. 

When case is dismissed, instruct family to boil 
patient's dishes well, jnit bedding out of doors in the 
sunshine, and disinfect room (bed, walls, furniture, 
etc.); this can be done very thoroughly by scrubbing 
well with soa]) and water. 

Pneumonia Case. — Orders: General care; saline rectal 
irrigation; mustard i)laster to entire chest until skin 
reacts; alcohol sponging; mustard foot bath; cold 
compress around chest. 

Place paper napkin on table and get out all the neces- 
sary things from bag. Alcohol (for cleansing ther- 
mometer); green soap (for washing hands); vaseline 
(to lubricate thermometer and rectal tube) ; boric acid 
(for mouth wash); rectal tubes; tooth-picks; scissors; 
cotton; mustard; old piece of cloth to make mustard 
plaster; small piece of cloth or gauze to make mustard 
bag for foot bath; glass connecting tube; douch bag; 
toilet soap; towel; wash cloth; pan for return of irri- 
gation; clean clothes for patient and for bed; rectal 
thermometer; safety-pins; a piece of oilcloth or oiled 
silk to cover compress on chest; wash basin; small 
bowl or dish for the alcohol sponge; paper bag for 



DIPHTHERIA, SCARLET FEVER, MEASLES 237 

waste material; glass and teaspoon to prepare mouth 
wash; comb. 

Prepare mustard plaster and i)lace on a warm platter 
or plate to warm; prepare mustard bag for foot bath 
(1 tablespoonful of mustard to 1 quart of water; for 
plaster, 1 to unless otherwise instructed); pre- 
pare saline solution for irrigation, using 1 teaspoonful 
of salt to 1 pint of water; hang bag in a convenient 
place near patient; prepare boric solution for mouth; 
if patient is a child, prepare tooth-pick swab for cleans- 
ing nose. 

Protect l>e(l (or pillow on table) with oilcloth; take 
"T. P. R." and record in note-book; place mus- 
tard plaster around chest; hold in place by a towel 
fastened in front with safety-pins; bring buttocks to edge 
of bed or pillow; with patient lying on left side, give 
saline irrigation, having someone hold pan to catch 
return; wash rectal tube and put on to boil; if patient 
is a child, protect with a diaper in case there should be 
further return; remove mustard plaster if skin is 
reddened; wash mouth, cleanse nose, give bath, 
comb hair, apply cold compress around chest, protect- 
ing with a piece of oilcloth or oiled silk, held in place by 
covering with a small towel or diaper and fastening in 
front with safety-pins; put on gown, make bed, give 
mustard foot bath, using friction; apply warm bottle 
to feet and ice-cap to head. Instruct family about 
changing compress, giving medication and nourishment, 
keeping window open, etc. In p.m. same treatment is 
given, giving an alcohol sponge instead of the cleansing 
bath. 

Typhoid Case. — Orders. — General care, cleanse mouth, 
alcohol sponging, enema, typhoid precautions. 



238 INFECTIOUS DISEASES AND PREVENTION 

Clear the room as much as possible of all unnecessary 
articles. Prepare a solution of chloride of lime in a 
large pail, })asin, wash-boiler, or wash-tub by placing 
chloride of lime (i ])()und to 1 gallon of water) in four 
thicknesses of gauze and dissolve in the j)an of water. 
Prej)are a solution for the hands, lysol 2 per cent. (1 
teaspoonful to 1 (piart of water). Collect the necessary 
dishes and mark with adhesive; prepare solution for 
cleansing mouth (boric, listerine, etc.) if tongue is 
furred; j)re})are a solution of equal parts of lemon juice 
and glycerin. lla\e fannly provide their own vaseline 
for tiiermometer, rubber catheter, or enema tip, 
alcohol, toilet paper, etc. (if possible). 

Typhoid thermometer should be marked and kept 
separate. 

Typhoid apron or gown should be marked by pinning 
a safety-pin on the side of the apron which is turned 
toward the patient. This side should be folded in and 
the apron placed in a paper bag and left on bedside 
table when nurse has finished giving care. When 
apron is soiled, place it in the chloride of lime solution 
with the other clothes; have family wash and iron it 
for next visit; this should be done also at close of case, 
so that apron may be returned to office properly dis- 
infected. 

Take out only the necessary articles from the bag, 
place on paper napkin; thermometer, alcohol, cotton 
gauze (for chloride of lime), lysol, vaseline, paper bags, 
paper napkins, adhesive, wooden spatulas (to split and 
wind with cotton to apply glycerin and lemon juice to 
tongue), bedside notes, etc. Prepare solutions, mark 
utensils, prepare enema; have some member of family 



DIPHTHERIA, SCARLET FEVER, MEASLES 239 

bring necessary articles to work with (bed-pan, basin, 
for bath, comb, soap, clean linen, etc.). Take tem- 
perature, pulse, and respirations. See that bed is 
protected with rubber or oilcloth; give enema; give 
bath (be careful about abdomen); alcohol rub if neces- 
sary; cleanse mouth and tongue; comb hair; make bed 
(always have bed protected by rubber and draw sheet) . 
As nurse removes clothing from patient or bed it should 
be placed in the chloride of lime solution to remain 
for two hours, then washed and boiled. When patient 
is removed from bed-pan, sprinkle freely contents of 
bed-pan with chloride of lime, making sure that there 
is always enough moisture in vessel to dissolve lime, 
and allow to remain standing at least a half-hour 
before emptymg. Prepare bedside table; leave paper 
bag and toilet paper for patient to use for expectoration; 
write up bedside notes; remove apron and fold and put 
in paper bag; soak hands well in lysol solution; wash 
hands and place articles back in bag. Instruct family 
about typhoid precautions (if possible do not permit 
person who does the cooking to take care of the patient), 
diet, ventilation, etc. 

P.M. visit; "T. V. R." Wash face and hands; 
alcohol sponge or alcohol rub; cleanse mouth; arrange 
bed. 

Bath water may be placed on stove and boiled up 
before emptying. 

Solutions for clothes and hands should be changed 
twice a day if necessary. 

Erysipelas. — Erysipelas cases are to be visited after 
all other patients have been seen for the day. 

A pasteboard box containing all necessary articles 



240 IXFECTIOrs DISEASES AXD PREVENTION 

for the patient is to i)c taken to the liome and left in tlie 
patient's room. Xurse's hasj: is not to he taken into 
patient's room. Kul^her <::lo\es and a <i:o\vn (with pin 
attaehed to side worn toward patient) to he left in 
j)atient's room. 

Xnrse's coat, hat, and ha<i: to he left in a room 
farthest from patient's. After nurse has remoxed her 
hat and coat, take from ha^, lysol, green soap, and 
hrush. Pre])are a 2 per cent, lysol solution (1 teaspoon- 
ful to 1 quart of water) for hands. 

After nurse has gi\-en the necessary care, she is to 
soak lier hands well in the lysol solution, wash hands 
and put things hack in hag. 



CHAPTER VII. 
PERSONAL HYGIENE. 

Personal hygiene is the science and the art of the 
preservation and the promotion of individual health 
and life. Its purpose is the prevention of constitutional 
diseases and the increase of the vital force of resistance 
of the human body. 

The causes of constitutional diseases depend less upon 
the environment of the individual, and more upon his 
personal modes of living, habits, and conformance with 
the laws of nature and rules of health. To combat 
infectious diseases we must improve environmental 
conditions common to many persons and communities 
and promote public health by municipal, social, and 
public health measures. To combat constitutional dis- 
eases we must depend on vital force and resistance of 
the human body upon the following by each individual 
of the proper rules of hygiene and the avoidance of 
anything that may be injurious to life or detrimental 
to health. 

Although giant strides have been made in the progress 
of prevention of infectious diseases, very little com- 
paratively has been done to promote individual health 
and to prevent the incidence of constitutional disease. 
Indeed, while we have succeeded in very materially 
reducing the mortality and morbidity from infectious 
diseases and in increasing the length of life, there has 
16 



242 PERSONAL HYGIENE 

been unfortunately an increase in mortality of the 
middle-aged and of the constitutional diseases -of the 
higher age groups. 

According to Dublin' all age groui)s up to and in- 
cluding fii) to 44 show decrease in mortality-rates for 
males for 1911 in c()in])aris()n with those for 1900, the 
percentage of decrease ranging from 27.00 for the age 
group of 5 to 9, to 3.70 at the age group of 35 to 44. 
From this age group onward the rates for 1911 are per- 
sistently higher than for the earlier date, the greatest 
(liH'erence being for the age period of 55 to 04, when 
the percentage of increase reaches 0.92. It has been 
found that this increase is due to the increase of mortal- 
ity from constitutional diseases. There has, for in- 
stance, been the following increase from 1900 to 1910 
in the mortality from the following diseases: 

Cancer 30.6 per cent- 
Diabetes 60.0 

Organic diseases of the heart . . . 39.3 " 

Diseases of the arteries .... 396.2 

The diseases from which persons at the higher age 
groups succumb are mostly those of the heart, arteries, 
and kidneys. The main problems therefore are those of 
prevention of the constitutional diseases, due to the 
impairment of the circulation and elimination. 

The nurse, in performing her multifarious duties in 
public health work, must not only be able to educate the 
public and the individuals under her care in the pre- 
cepts of public and personal hygiene, but is also expected 
to practise what she preaches, be in robust and perfect 

^ Possibilities of Reducing Mortality at the Higher Age Groups, 
Louis I. Dublin. 



ACTIVITY AND REST 243 

health, and follow the right methods of living and the 
precepts of her hygienic teachings to others. 

Activity and Rest. — ^Muscular activity is a necessary 
physiological state of every animal being. Normal 
rhythmic contraction and expansion of the muscular 
fibers of the body are necessary for the well-being of 
the individual. Prolonged disuse of the muscles lead 
to atrophy and death. Oxidation and bodily metabo- 
lism depend upon muscular work. Hence normal liv- 
ing demands a certain modicum of activity of all bodily 
organs, exercise of voluntary muscles, and general 
activity upon the part of the individual. 

Exercise, while absolutely necessary for well-being, 
must, however, be carried on with care and modera- 
tion. Overuse of certain organs and too violent exer- 
cise may be as detrimental to health as lack of use or 
disuse of the organs. Exercise must also be moderated 
according to age, occupation, and condition of the 
individual. What is permissible to younger persons 
may do harm if attempted by the aged. Persons 
engaged in strenuous occupations have all the exercise, 
or, perhaps more, than they need within their occupa- 
tions. Persons who are engaged in sedentary work 
need considerable exercise outside of their occupation. 
For these, walking is perhaps the best exercise if pur- 
sued in the outside air and continued at least an hour 
a day. Bodily exercise should not mean all work, but 
should also include play. The value of recreation and 
play has not been recognized as well as it should. In all 
activities involving bodily exercise, play and recreation 
should be given their time and part. 

Indispensable as are activity and work to the well- 
being of the individual, they would do untold harm if 



244 PERSOXAL HYGIENE 

not followed and interrupted by periods of rest. Rest 
and sleep are as indispensable as work and play. Per- 
haps not all of ns are able to take and enjoy at least 
eight hours of the twenty-four for sleej), but all should 
try to get as near the ideal number of hours of sleep as 
possible. Nurses, especially, are often coni])elled to go 
long stretches without sufficient sleep and to do nuich 
work without sufficient rest. That insufficient slcc]) and 
inadequate rest nrc a great detriuient to the health 
of the ])ers()ii no one knows better than the trained 
nurse. Hence it is important for her not only to take 
care for her own health in this respect, but also to teach 
to others the gospel of proper rest and recreation. 

Food and Dietetics. — Food is necessary to repair the 
bodily wastes and to replenish the energy lost by the 
constant oxidation going on within the body. The 
amount of food required each twenty-four hours for 
each individual, or the daily ration of food is of impor- 
tance to the body metabolism and to the well-being 
of each individual. It is difficult to lay down fast rules 
or definite standards as to the exact amount of food 
needed for each individual. Not only do authorities 
differ greatly on the subject, but there is naturally 
a great difference in the individual requirements, a 
difference based on age, sex, height, weight, activities 
and other factors. It is natural that children need 
less food than adults; females less than males; small 
persons less than large; those at rest or in inactive 
occupations less than those robust, active and perform- 
ing strenuous work. 

INIodern scientists have determined that the average 
person requires between 2500 and 3500 calories every 
twenty-four hours. The smaller number of calories 



THE CALORIC VALUE OF FOOD 245 

is required by the average adult engaged in sedentary 
or clerical work, while the larger number of calories 
is required by the average individual in active and 
strenuous occupations. An increase or decrease of 
from 200 to 500 calories in the necessary daily ration 
may not lead to much harm in the young and growing 
age, but may be detrimental to the health of persons 
above forty, whose metabolism is much slower and 
more easily disturbed. 

The comparative amount of protein which must be 
taken in the daily ration is still a subject of controversy. 
There is no doubt that Americans especially consume 
too great a proportion of protein in their food, because 
of their excessive use of foods which have a high pro- 
tein content, such as fish, meat, eggs, cheese, etc. 
Modern scientists claim that protein should not exceed 
10 per cent, of the total nutriment taken in. This 
would allow from 250 to 350 calories of protein for the 
daily ration. Fifty to 100 grams of protein nutriment 
a day should be more than sufficient for all bodily 
requirements. 

The proportion of fat and carbohydrates in the daily 
ration is comparatively of less importance, although a 
good proportion would be 30 per cent, of fat and 60 
per cent, of carbohydrates. 

The Caloric Value of Food. — There is as yet a great 
deal of misconception as to the approximate caloric 
value of the portions of ordinary food daily consumed 
by individuals. The following table,^ giving the 
ordinary common foods, with the hundred calories 
value thereof, may be of interest to nurses in their 
calculations of balanced rations: 

^ From Fisher and Fisk, "How to Live." 



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PERSONAL HYGIENE OF THE CHILD 249 

Elimination. — The metabolism of the body imphes 
not only the intake of foods and their proper digestion 
and assimilation in the body, but also the elimination 
from the body of the waste products of digestion, 
metabolism, and oxidation. 

The skin, the kidneys and the intestines are the prin- 
cipal bodily organs taking care of the proper elimination 
of bodily wastes. 

The hygiene of the skin implies proper care, frequent 
and periodical bathing, and proper clothing for the body. 

The activities of the kidneys and the proper elimina- 
tion of bodily wastes through the kidneys and urinary 
canals are the most important functions of the body. 
The efficiency of these excretory organs is absolutely 
necessary to health and life. Disturbances of these 
organs lead to ill-health, disease and premature mor- 
tality. 

Intestinal elimination is another of the most impor- 
tant functions of the body. Intestinal stasis and habit- 
ual constipation are foes of health and life. The in- 
gestion of foods containing a large percentage of 
cellulose, the eating of vegetables, bran constitutents 
of cereals, and other bulky foods are necessary for the 
proper intestinal digestion and elimination. Bodily 
activity and exercise are also conducive to the same 
result. 

Personal Hygiene of the Child. — This differs in its 
practical ai)plication according to age. There is neces- 
sarily a difference in the rules and regulations for the 
care and promotion of health of infants, of children 
under school age, of school children, and of adolescents. 
The general principles, however, are identical with 



250 PERSOXAL HYGIENE 

those wliich have l)een described as rehiting to all 
persons, whether children or adults. The rules of 
health are essentially' those of proper feeding, clothing, 
exercise, bathing, and physical and mental training. 
Infants and young children demand more attention 
Mild closer supervision than do the older children. 

Milk and milk foods ;irc almost the exclusive articles 
of food for infants under one year. There is at present 
a tendency to regard the digestion of raw cows' milk 
as diflicnlt in view of its immediate curdling within 
the stomach. The objections against ])asteurization 
and sterilization of milk for infants' foods are not 
considered serious. The modification of milk by chang- 
ing the percentage of the proteid and fat constitutents 
has become a regular practice in infant feeding. 

As to clothing of infants, the opinion seems to 
prevail that woollen garments have the advantage over 
cotton and linen. The exposure of the legs or other 
parts of the body is to be avoided. 

Bathing in tepid water, 100° to 110° F., is best done 
before the last feeding in the evening. Regularity 
in the discharge of the bowels should be encouraged. 
Sponging with water, 70° to 90° F., is a good routine 
practice in the morning. 

As the child grows older, cereals, fruits, vegetables, 
and bread products may be added to the diet. The 
feedings should be at regular periods. Evening bathing 
in tepid water and morning sponging with cool water 
should be continued, and physical exercise and play 
should be encouraged. 

Young infants as well as older children should be 
kept in the fresh air as much and as long as possible. 



PERSONAL HYGIENE OF THE CHILD 251 

Outdoor play and exercise for older children should be 
encouraged. Sugar and confectionery seem to be well 
borne and digested by children. They should not be 
used in excess, however, or in the intervals between 
feedings, but should be given during each feeding. 

A slight rise of temperature in children is no indi- 
cation of pathological conditions, as it may be caused 
by overfeeding, constipation, diarrhea, excitement, etc. 

The care of infants and children during sickness 
cannot be discussed here. 

The hygiene of the school child has been discussed 
in Chapter IV, but mention must be made here of 
the care of school children in their homes. The gain 
is slight if hygienic conditions surround the child in 
the school, but are neglected in the home. Instruc- 
tions should be given to mothers in the care, feeding, 
etc., of the school child while it is in the home, so as 
not to counteract the beneficial influences of school 
life. The most important rule for the care of the school 
child while in its home is the proper provision of 
substantial and digestible breakfasts so that the child 
does not leave the house fasting or hungry. After 
the child is confined within the school for a number 
of hours it is the duty of its parents to keep it in the 
fresh air and to allow it to play and exercise outdoors 
during the part of the day when it is out of school. 
Too many children are given home tasks and too many 
children are unfortunately compelled to do some home 
work during the afternoons and evenings after school 
hours. During adolescence the nervous equilibrium is 
easily disturbed and much intelligent care is necessary 
to prevent nervous break-down. Intelligent instruc- 



252 PERSOXAL HYGIENE 

tion in the elements of i)liysi()l()<2:y and in sexnal hygiene 
is necessary for the promotion of the liealth of the 
child and for the prevention of various indiscretions 
and abuses. 

Personal Hygiene of the Aged.— The j)ersonal hygiene 
of the aged diil'ers <;rcatly from the hygiene of younger 
persons. There is considerable difference in the exact 
age wlien a person seems or becomes old. Some are 
old at thirty, while others are young at seventy; nor 
does old age come on suddenly without previous due 
notice. Rather it creeps on gradually and slowly. A 
person is said to be as old as his heart and his arteries. 
The main indications, therefore, for the care of the 
aged is in the care of the circulatory system and the 
])revention of overstrain and fatigue. 

Indiscretions, overindulgence, exposure, and irregular 
life are more dangerous in the old than in the young, 
for the recuperative powers are much lessened in the 
aged. ]\Iuch less sleep is needed by the aged, although 
more prolonged periods of rest are necessary. Too 
strenuous exercise must be avoided. There is need 
of much less food and there is greater danger from 
overfeeding. Bathing with cold water must be done 
with care, and perhaps avoided, unless the body is 
accustomed to the effects of cold water. The effects 
of certain shocks are dangerous. Warm woollen 
clothing should be worn in moderate as well as in cold 
weather. The best exercise for the aged is walking 
outdoors. Golfing is considered a good exercise for 
the aged who can afford it. There are very few 
hard-and-fast rules for the aged as well as for the 
young. Constitutional differences and environmental 



PERSONAL HYGIENE OF THE SICK 253 

conditions invalidate universal and uniform laws of 
health. 

Personal Hygiene of the Sick. — The rules guiding 
the nurse in the care of the ill, the convalescent, and 
the diseased must necessarily differ according to the 
age and condition of the sick person, and especially 
according to the character, degree, and severity of the 
disease from which the person suffers. Here, again, 
common sense and intelligence are perhaps more 
important than set rules and regulations. 

The feeding of sick persons must be done with care 
and according to the instructions of the physician, 
who alone is competent to judge of the necessary 
amounts of food required as well as of the kinds of 
food needed. As a rule, sick persons need more 
digestible and better prepared foods, at more fre- 
quent intervals, than do well persons. The nurse 
should learn the art of preparing certain foods and 
articles of diet which are appropriate for the sick. 

The bathing of sick persons is a procedure which 
should be done only according to the directions of a 
physician. Cold water must be used judiciously and 
with great care. Bed-ridden patients need special care 
to prevent bed-sores. This can be accomplished by 
proper care of the bed and bedding, by smoothing 
out all wrinkles in the bedding, by appropriate sup- 
port under the sacrum and heels, which are the places 
principally affected by bed-sores, and by massage of 
the body and special parts of the body as well as by 
alcohol rubs, inunctions, etc. 



INDEX 



A 



Accidents in occupations, 186 

prevention of, 186 
Acetylene gag, 28 
Adulteration of foods, 99 

of meat, 100 

of milk, 128 
Aged, personal hygiene of, 252 
Agents of transmission of in- 
fectious diseases, 198 
Air, carbonic acid in, 30 

increase and decrease of, 
33 

changes due to combustion 
and illumination, 31 
in houses, 31 

composition of, 30 

confined, 32 

character and effects of, 32 

diffusion of, 30 

ill effects caused by impure,33 

impurities in, 31 

influence of, upon health, 32 

moisture in, 30 

sewer, 61 
Albuminoids in milk, 117 
Animals, 79 

domestic, 79 
Aqueducts, 48 
Arsenic poisoning, 179 
Artificial light, 27 



B 



Back |)ressure tra])s, ()5 
Bacteria, infection of meat b}' 
102 
in milk, 112, 132 



! Bacterial diseases, 195 
Bacteriology, 19 
Bath tubs, 70 
Berkefeld filter, 53 
Blended milk, 123 
Brass pipe in plumbing, 59 
Building, school, 153 
Butter, 124 
Buttermilk, 124 



Caloric value of foods, 245 
Carbohydrates in foods, 91 
Langworthy on, 93 
Rubner on, 93 
Carbon dioxide, 74 

monoxide, 74 
Carbonic acid in air, 30 
Casein in milk, 117 
Cellulose in foods, 92 
Central heating, 39 
Cesspools, 57 
Chadwick on sanitary science, 

19 
Cheese, 125 
Chemical cleansing of water, 51 

composition of foods, 90 
Child labor, 182 

personal hygiene of, 249 

school, 148 
Chimneys, role of, in ventila- 
tion, 35 
Cholera, milk and, 114 
Cleaning of house, 81 

of school building, 156 
Coal gas, 28 
Colostrum in milk, 120 
Composition of water, 42 



256 



INDEX 



Condensed milk, 124 

Conservation of human re- 
sources, 20 

Construction of school building, 
153 

Contagious diseases of school 
child, IGl 

Cost of foods, 94 

Cow's milk, 116 

Cream, 122 

gauge in milk testing, 143 
])roducti()n of, 122 

Cresols, (li.sinfe(;tion hy, 213 



Dangers in occupations, 177 

prevent i<m of, 1<S5 
Definition of disinfection, 209 

of foods, S9 

of hvgiene, 18 

of niilk, 127 

of sanitary art, 18 
law, 18 
science, 18 

of sanitation, 18 

of traps, 63 

of ventilation, 34 
Deterioration of milk, 131 
Dietetics, 93, 244 
Diphtheria, milk and, 114 

nurse in. 231 
Disease, insects in, 81 

main causes of, 22 

relation of, to housing, 24 

water and, 43 
Diseases associated with hous- 
ing conditions, 24 

due to milk, 113 

infants', milk and, 113 

of occupations, 169 

parasitic, due to meat, 101 

possible prevention of, 22 

water-borne, 44 
Disinfection, 208 

chemical, 212 

cresols in, 213 

definition of, 209 

difficulties of, 208 

formaldehyde gas in, 215 

lime in, 215 



Disinfection, physical, 210 
practice of New York City 
Health Department in, 218 
of rooms, 216 
of soiled wash, 218 
sulj)hur dioxide in, 215 
of walls, 216 
Distillation, water, 50 
District nurses, 227 

general duties of, 228 
outfit of, 22S 
Dust, dangers of, in house, 78 
and dirt, 76 
dangers of, 77 
Pruclilen, Dr., on removal 
of, 77 
in occupations, 185 
prevention of, 185 
Dysentery, milk and, 114 



E 



Effect of occupation on health, 

170 
Electricity, heating by, 39 
Emergency and first-aid treat- 
ment in schools by nurse, 162 
Endemic diseases, 194 
Epidemic diseases, 194 
Erysipelas, nurse in, 239 
Estimate of food values, 92 
Expectation of life, 20 
Exposure in infectious diseases, 
193 



Factories, functions and duties 

of nurse in, 189 
Factory inspection, 186 
Farr on sanitary science, 19 
Fats in foods, 91 

in milk, 117 
Ferments in milk, 118 
Feser's lactoscope, 144 
Filters, Berkefeld, 53 
Filtration of water, 50, 51 
Fire escapes, 26 

exits in case of, 26 

protection, 25 
in housing, 25 
Fish foods, 109 



INDEX 



257 



Fisher, Professor I., on prolon- 
gation of life, 22 
First-aid kits, 189 
Fixtures, plumbing, 66, 70 
Fomites, 200 
Foods, 89 

adulteration of, 99 

baking of, 95 

boiling of, 95 

caloric value of, 245 

canning of, 98 

carbohydrates in, 91 

care, storage and preservation 
of, 96 

cellulose in, 92 

chemical composition of, 90 

cooked, 95 

cost of, 94 

definition of, 89 

dietetics and, 244 

drying of, 97 

estimate of values of, 92 

fats in, 91 

frying of, 96 

game, 108 

high temperatures of, 98 

milk as, 110 

mineral matters in, 91 

poultry, 108 

preparation of, 93, 95 

prepared, 95 

preservation of, 96 

protein in, 90 

raw, 95 

roasting of, 96 

salting and pickling of, 98 

smoking of, 98 

steaming of, 96 

stewing of, 95 

storage of, 96 

temperature influence on, 97 

vitamins in, 92 

water in, 91 
Fore-milk, 121 
Formaldehyde gas, disinfection 

by, 215 
Fumes in occupations, 180 



Game, 108 
Gas, acetylene, 28 
17 



Gas, coal, 28 

fixtures, 29 

heating by, 39 

service, 29 

sewer, non-existent, 61, 62 

shades, 29 
Gases, carbon dioxide, 74 

carbon monoxide, 74 

fumes and vapors in occupa- 
tions, 180 

house, 74 

in occupations, 180 

poisons and, 74 

smoke and coal-gas, 75 

water, 29 
Glass, milk, 27 

plate, 27 

prism, 27 

in windows, 27 



Habitations, hygiene of, 24 
Health Department, New York 
City, practice in regard to 
disinfection after infectious 
diseases, 218 
insurance, 187 
lactometer for milk testing, 

146 
occupations and, 166 
water and, 42 
Heating, 37 
central, 39 
electricity in, 39 
gas in, 39 
grates in, 38 
hot-water, 40 
local, 38 

means and methods of, 38 
regulation of, 41 
school, 155 
steam in, 41 

advantages of, 41 
stoves in, 39 
Ileeren pioscope, 144 
Home work, 174, 184 
Hot-water heating, 40 

sui)ply of, 49 
House cleaning, 81 

means and methods of, 86 



258 



INDEX 



House drain, 00 

drainage, 54 

insects in, SO 

|)()is()ns, 75 

sewer, ()() 

waste mat t<'rs f)f , 73 

water sui)i)ly of, 48 
Housing eonditioHvS, 24 
fire protection in, 25 
important factors in, 25 

safety, 25 
Humidity, 31 

al)s()lute, 31 

relative, 31 
Hygiene, 17 

delinitions of, 17 

function of, 20 

of lial)itation,s, 24 

of meat, 101 

of occupations. Kit) 

personal, 18, 241 

public, 18 



Ice, 53 

h)oxes, 54 
Illumination, light and, 26 
Immunity in infectious diseases, 

204 
Impurities, water, 42 
Incubation in infectious dis- 
eases, 193 
Industrial betterment, 181 
factors, 171 
age and, 172 
personal, 171 
poisons, 179 
Infant diseases, milk and, 113 

mortality, milk and, 113 
Infectious diseases, 190 
bacterial, 195 
disinfection in, 208 
endemic, 194 
epidemic, 194 
exposure to, 193 
fomites in, 200 
incubation in, 193 
immunity in, 204 
artificial, 205 
natural, 204 



Infectious diseases, immunity 
in, passive, 207 
inoculation in, 206 
modes, vehicles and agents 

of transmission in, 198 
morbific agents, 194 
nurse in, in diphtheria, 231 
district, 227 

general duties of, 228 
outfit of, 228 
in erysijjelas, 239 
in measles, 231 
in i)neumonia, 236 
in scarlet fever, 231 
in tuberculosis, 230 
in tyi)h()id fever, 237 
period of invasion of, 193 
portals of entry of, 196 
principles and j^ractice of 

prevention of, 201 
prophvlaxis in, methods of, 
^203 
social, 223 
role and function of nurse 

in prevention of, 226 
sanitary measures in, 225 
Inoculation in infectious dis- 
eases, 206 
Iron pipes in plumbing, 59 
Insects, 80 
in disease, 81 
in house, 80 
Inspection of milk, 141 
Intensity of light, 27 



Joints of pipes in plumbing, 59 



Kefir milk, 128 
Koumiss milk, 128 



Lactometer, 145 

of Health Department of New 
York City, 146 



INDEX 



259 



Lactometer, Quevenne's, 145 
Lactoscope, Feser's, 144 
Langworthy on protein and car- 
bohydrates, 93 
Lead pipes in plinnl)ing, 59 

poisoning, 179 
Length of life, increase of, 21 
Life, length of, increase of, 21 
Light, artificial, 27 
illumination and, 26 
intensity of, 27 
natural, 26 

amount of, 26 
sunlight, 26 
Lighting of school building, 155 
Lime, disinfection by, 214 



M 

Machinery in occupations, 

safeguarding of, 175 
Measles, milk and, 114 

nurse in, 231 
Meat and meat supply, 100 
adulteration of, 104 
characteristics of good, 104 
cold storage of, 105 
hygiene of, 101 
infection of, by bacteria, 102 
parasitic diseases due to, 101 
preservation of, 105 
chemical, 106 
heat, 107 
sanitary supervision of, 107 
tapeworms in, 101 
toxins and ptomains in, 102 
trichina in, 101 
unfitness of, 103 
causes of, 103 

diseases of animals, 103 
infection by persons, 104 
Mechanical ventilation, 3() 
Medical inspectors in schools, 

159 
Mercury in occupations, 179 
Milk, abnormal, 121 
adulteration of, 128 

by a(l(Uti()n of chemicals, 
130 
of coloring matter, 130 
of skim milk, 130 



Milk, adulteration of, by addi- 
tion of water, 12S 

])y extraction of cream, 129 

by skimming, 129 

by watering, 129 
albuminoids in, 117 
appearance of, 118 
bacteria in, 112, 132 
blended, 123 
butter in, 124 
buttermilk, 124 
casein in, 117 
cholera and, 114 
color of, 119 
colostrum in, 120 
composition of, 116 
condensed, 124 
cow's, 116 
definition of, 116 

official, 127 
deterioration of, 131 

causes of, 131 
diphtheria and, 114 
diseased bacteria in, 113 
diseases due to, 113 
dysentery and, 114 
fat in, 117 

ferments and gases in, 118 
fore, 121 

importance of, as food, 110 
impurities of. 111 
infant diseases, relation to, 
113 

mortality due to, 113 
inspection of, 141 
kefir, 128 
koumyss, 128 
measles and, 114 
mineral matter in, 118 
preservation of, 131 

chemical, 136, 139 
objections to, 140 

cold, 136 

dryness, 134 

high temperature, 135 

low tem})erature, 134 

mean temperature, 135 

pasteurization, 13S 
llosenau on, 138 

sterilization, 137 
products, 122 
proteids, 117 



2()0 



IXDEX 



Milk, roartion of, 119 
scarlet fovor and, 114 
skim. 12;i 
solids in, 117 
s])Ocifi(' {iravity of, 119 
standards, official, 12() 
strijjpings, 121 
sufjar in, 117 
tcstiiifi: of, 141 

l)V chemical examination, 

'147 
hy croani piuj^c. W'A 
by Health I)ei)artment of 
New ^'ork, lactometer in, 
14() 
hy lactometer, 145 
hv lactosc()j)e (Keser), 144 
nu'thodsof, 141 
chemical, 141 
pliNsical, 141 
\)\ |)hvsical examination, 

!)y piosrope (Heeren), 144 
precautions in, 142 
Quevenne lactometer in, 

145 
specific gravity in, 145 
tuberculosis and, 115 
typhoid and, 114 
variations in, 119 
whey, 128 
Mineral matter in foods, 91 
in milk, 118 
in water, 42 
Modes of transmission of infec- 
tious diseases, 198 
Momentum traps, 64 
Morbidity in occupations, 168 
MorVjific agents, 194 
Mortality rate, 21 
decrease in, 21 

from various diseases, 21 
in occupations, 167 
Myopia in school children, 150 



N 



Natural light, amount of, 26 

ventilation, 34 
Nightingale, Florence, 23 
Nurses, district, 227 



Nurses, district, general duties 
of, 22S 
outfit of, 228 
factory, duties of, 189 

functions of, 188 
increase in number of, 23 
in infectious diseases, 226 
in diphtheria, 231 
in erysipelas, 2'M) 
in measles, 231 
in pneumonia, 236 
role and functions in pre- 
vention of, 226 
in i)roi)hylaxis, 23 
in scarlet fever, 231 
in tuberculosis, 230 
in tvphoid, 237 
school, 158 

advice as to physical de- 
fects in children, 162 
emergency and first-aid 

treatment in, 162 
functions and duties of, 158 
home visits to children by, 

159 
treatment of certain dis- 
eases by, 163 



Occupations, accidents of, pre- 
vention of, 186 
child labor in, 182 
dangers of, 177 

prevention of, 185 

specific, 177 
diseases of, 169 
dusts in, 177 

animal, 178 

metallic, 178 

mineral, 178 

prevention of, 185 

vegetable, 178 
effect of, on health, 170 
factory inspection in, 186 
first-aid kits in, 189 
health and, 166 

insurance and, 187 
home work, 174, 184 
hygiene of, 166 
industrial betterment in, 181 



INDEX 



201 



Occupations, industrial factors 
in, 171 
personal, 171 
age, 172 
poisons, 179 
arsenic, 179 
gases, fumes and vapors, 

180 
lead, 179 
mercury, 179 
phosphorus, 179 
machinery in, 175 

safeguarding of, 175 
morbidity in, 168 
mortahty rate in, 167 
nurse in, 188 
duties of, 189 
functions of, 188 
Ogle's tables on, 167 
tuberculosis and, 168 
women's labor in, 172, 182 
working conditions in, 176 
workplace, 173 
sanitation of, 183 
Ogle's tables on occupations, 

167 
Organic matter in water, 43 



Pail system of sewage disposal, 

55 
Parasites in water, 43 
Parasitic diseases due to meat, 

101 
Pasteurization of milk, 138 

Rosenau on, 138 
Period of invasion in infectious 

diseases, 193 
Personal hygiene, 241 

activity and rest and, 243 
of aged, 252 
of child, 249 

food in, caloric value of, 
245 
dietetics and, 244 
of sick, 253 
PetterkofTer on sanitary science, 

19 
Phosphorus in occupations, 
179 



Physical defects in school chil- 
dren, 162 
examination of milk, 143 
Pioscope, Heeren's, 144 
Pipes in plumbing, 59, 66 
Plumbing, 58 
fixtures, 66, 70 
bath tubs, 70 
refrigerators, 71 
pipes, 59, 66 
brass, 59 
house drain, 60, 67 

sewer, 60 
iron, 59 
joints of, 59 
lead, 59 

materials for, 58 
rain leaders, 60, 70 

vent, 65 
sediment, 71 
size of, 60 

soil and waste, 60, 68 
branch, 68 
construction of, 68 
Pneumonia, nurse in, 236 
Poisons, house, 75 

industrial, 179 
Portals of entry in infectious 

diseases, 196 
Precautions in testing milk, 142 
Preparation of foods, 93, 95 
Prepared foods, 95 
Preservation of foods, 95 
of meat, 105 
of milk, 131 
Privies, 56 

construction of, 56 
sanitary, 56 
Privy vaults, 55 
Products of milk, 122 
Prophylaxis in infectious dis- 
eases, 203 
role of nurse in, 223 
social measures and, 223 
Proteids in milk, 117 
Protein in foods, 90 

Langworthy on, 93 
Uubner on, 93 
Prudden on dust and its dangers, 

77 
Ptomaines in meat, 102 
Puriticaticm of water, 49 



262 



INDEX 



Quevenne's lactoni(>tcr, 145 



Rain loader, (iO, 70 

water, 45 
Kef rinera tors, 71 
Roscnau on milk jJMstcurization, 

13S I 

Riihiior on protein and carho- | 

hydrates, 93 



S 



Sanitary art, definition of, 18 
law, definition of, IS 
measures in infeetious dis- 
eases, 225 
seienee, definition of, IS 
supervision of meats, 107 
Sanitation, definition of, IS 
Scarlet fever, milk and, 114 

nurse in, 230 
School building, 153 
cleaning of, 15G 
construction of, 153 
furniture in, 157 
heating of, 155 
lighting of, 155 
sanitation of, supervision 

of, 157 
ventilation of, 155 
water supply of, 156 
child, 148 
age of, 149 
care of, 157 

contagious diseases in, 161 
defects in, 151 
physical, 160 
myopia in, 150 
teeth of, 150 
trachoma in, 165 
medical inspectors of, 159 
nurse, advice of, as to physi- 
cal defects, 162 
emergency and first-aid 

treatment by, 162 
functions and duties of, 158 



School nurse, home visits by 
159 
treatment of diseases by, 
163 
methods of, 1()4 
room. infhuMice of, 149 
Sediment pipes, 71 
SedinuMitat ion of water, 50 
Sewage disposal, 54 
methods of, 55 
combined, 58 
pail system, 55 
separate, 58 
water-carriage, 57 
Sewer air, 61 

dangers of, 61 
gas, ()1 

non-existent, 62 
Sick, i)ersonal hygiene of, 253 
Siphonage trai)s, 64 
Skim milk, 123 
Social measures of prophylaxis 

in infectious diseases, 223 
Soil j)ipes, 60 
Solids, milk, 117 
Sources of water supply, 45 
Specific gravity of milk, 119 
Steam, heating by, 41 
Sterilization of milk, 137 
Stoves, heating by, 39 
Strippings, milk, 121 
Subsoil water, 4() 
Sugar in milk, 117 
Sulphur dioxide, disinfection 

by, 215 
Sunlight, 26 
Surface w^ater, 46 



Tapeworms in meats, 101 
Teeth of school child, 150 
Temperature of foods, 97, 98 
Testing of milk, 141 
Toxins in meats, 101 
Trachoma in school child, 165 
Traps, 62 

back pressure in, 65 

definition of, 63 

evaporation in, 64 

loss of seal in, 63 



INDEX 



263 



Traps, monientuni in, 04 

sii)lu)iia^e in, 04 
Trichina in meats, 101 
Tuberculosis, milk and, 115 

nurse in, 230 

occupations and, 168 
Typhoid fever, milk and, 114 
nurse in, 237 



Underground water, 47 



Vapors in occupations, 180 
Vehicles of transmission of in- 
fectious diseases, 198 
Vent pipes, 65 
size of, 70 
Ventilation, 34 
definition of, 34 
devices for, 36 
differences of temperatures 

and, 35 
mechanical, 36 

advantages of, 37 
methods of, 35 
natural, 34 

role of chimneys in, 35 
of school buiklings, 155 
Vital statistics, 19 
Vitamines in foods, 97, 98 



W 

Waste matters, 73 
house, 73 
water and sewage, 73 



WixHte pipes, 60, 68 
Water, 42 

aqueducts, 48 

boiling of, 50 

l)orne diseases, 44 

characteristics of good, 44 

chemical cleansing of, 51 

composition of, 42 

disease and, 43 

distillation of, 50 

filters, 53 
Berkefeld, 53 

filtration of, 50, 51 

in foods, 91 

gas, 29 

hard or soft, 45 

impurities of, 42 

minerals, 42 

organic matter in, 43 

[)arasites in, 43 

purification of, 49 

relation of, to health, 42 

sedimentation of, 50 

supply of, 42 
hot, 49 
house, 48 
sources of, 45 
rain, 45 
subsoil, 46 
surface, 46 

underground, 47 
Water-carriage method of sew- 
age disposal, 57 
Water-closets, 71 

apartments, 72 

modern, 71 
Whey in milk, 128 
^^'indows, area of, 27 

character of, 27 
Women's labor, 172, 182 
Working conditions, 176 
Workplace, 175 

sanitation of, 183 






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